I guess I wouldn't say he is one of the most powerful mortals alive, but I would say he is a very talented detective. I changed some of his aspects and stats after revisiting some of the details from the show. I would think that 1% or less detectives operate at the level he functions at despite his inexperience with the supernatural.

Aspects

High Concept
"Psychic" Detective

Trouble
Rules, what rules?

Other Aspects
The Gift, I'll Believe you, Plenty of other peoples money

 Superb (+5)
# of slots: 1 Empathy
Great +4
# of slots: 3 Alertness, Investigation, Rapport
Good (+3)
# of slots: 3 Burglary, Contacts, Deceit
Fair (+2)
# of slots: 3 Conviction, Presence, Stealth
Average (+1)
# of slots: 3 Athletics, Driving, Endurance

Stunts & Powers

-1 Best Foot Forward
-1 Corner of My Eye
-1 Honest Lies
-1 Pick Pocket
-1 Quick Eye
-1 Read the Surface
-1 Scene of the Crime
-1 Won't Get Fooled Again

Quick Eye:
When examining a location for clues, your eye is quick to pick out the visual details. Your first Investigation roll to determine deeper details about a scene is two time increments faster than usual.

Scene of the Crime:
You have a practiced eye when combing over a crime scene. In such a circumstance, you gain +1 to your Investigation roll and arrive at your findings one step faster than usual on the time table.

Best Foot Forward:
People just like you, especially when you're deliberately trying to make a good first impression. You gain a +1 on your roll to make a good first impression, and failing that roll cannot give you a negative temporary aspect or make the situation worse.

Read the Surface:
You can get a sense of someone quickly when trying to read them. Your first attempt to read someone takes less than a minute of interaction, instead of the usual ten. Any subsequent efforts with the same person do not enjoy this benefit.
 Won't Get Fooled Again:
It only takes once for someone to lie to you before you start to wise up to it. Once you've discovered a particular person's lie for what it is, you gain a +2 on any future Empathy rolls when dealing with that liar. (This requires a small amount of book-keeping, but the benefits are worth it!)

Honest Lies:
Whenever incorporating a real, valuable piece of the truth (however marginally valuable it may be) into a lie, you gain a +2 on your efforts to pass off the untrue parts.

Pick Pocket:
Whether it's a simple bump-and grab or something more complicated, you're adept at getting people to pay attention to other things while you or an accomplice liberates their pockets of their contents. You may use the Deceit skill to perform pick-pocketing with no increases in difficulty. This includes the filching of small items from a desk or someplace similar. Targets of this action usually oppose with Alertness.

Corner of My Eye:
When successfully rolling Alertness passively to pick up on details, gain an additional 2 shifts. This reflects the ability to pick up on more pieces of information, but it does not improve the depth of that information (which would take things into the realm of Investigation).
 

How would one create Shawn Spencer?

So far here is what I have

Shawn Spencer

Aspects
High Concept
"Psychic" Detective

Trouble
A little too hands on

Other Aspects
Daddy's Little Monster, Psychic Detective,

Fantastic (+6)
# of slots: 2 Empathy, Investigation
Superb (+5)
# of slots: 2 Alertness, Rapport
Great +4
# of slots: 2 Deceit, Performance
Good (+3)
# of slots: 2 Athletics, Burglary
Fair (+2)
# of slots: 2 Conviction, Endurance
Average (+1)
# of slots: 3 Contacts, Presence, Stealth

Stunts & Powers

-1 Best Foot Forward
-1 Corner of My Eye
-1 Document Forging
-1 Honest Lies
-1 I Know Just the Guy
-1 Impersonator
-1 Listening
-1 Personal Magnetism
-1 Pick Pocket
-1 Quick Eye
-1 Read the Surface
-1 Scene of the Crime
-1 Won't Get Fooled Again

Quick Eye:
When examining a location for clues, your eye is quick to pick out the visual details. Your first Investigation roll to determine deeper details about a scene is two time increments faster than usual.

Scene of the Crime:
You have a practiced eye when combing over a crime scene. In such a circumstance, you gain +1 to your Investigation roll and arrive at your findings one step faster than usual on the time table.

Listening:
You can tune out your other senses and simply focus on your hearing, making you able to pick up faint sounds with astonishing clarity. Gain a +4 on your Investigation roll when Listening; however, your Alertness drops to Terrible while doing so, due to the exclusion of your other senses. If a conflict begins while you are Listening, it will take a full exchange for your Alertness to return to normal once you stop.

Impersonator:
Given a few hours to study someone's behavior and modes of speech, you may imitate their mannerisms and voice, using Performance instead of Deceit to convince someone you are that person. Without strongly controlling the circumstances (e.g., impersonating someone over the phone), such impersonations won't last very long. If combined with the Makeup Artist stunt and plenty of preparation, you may use either Performance or Deceit to pull off a full impersonation, using the better skill for all relevant rolls and getting a +1 against Investigation rolls trying to penetrate the disguise.

Personal Magnetism:
You have a calm confidence that others find appealing. When rolling Presence to establish a passive reaction to you, make the roll at +2.

Best Foot Forward:
People just like you, especially when you're deliberately trying to make a good first impression. You gain a +1 on your roll to make a good first impression, and failing that roll cannot give you a negative temporary aspect or make the situation worse.
 Read the Surface:
You can get a sense of someone quickly when trying to read them. Your first attempt to read someone takes less than a minute of interaction, instead of the usual ten. Any subsequent efforts with the same person do not enjoy this benefit.

Won't Get Fooled Again:
It only takes once for someone to lie to you before you start to wise up to it. Once you've discovered a particular person's lie for what it is, you gain a +2 on any future Empathy rolls when dealing with that liar. (This requires a small amount of book-keeping, but the benefits are worth it!)

Document Forging:
You are trained in the forging of official documents (such as ID, birth records, and the like) or letters. You can roll Deceit to create these documents, but using them or planting them where they will be of use (like in a library or government office) might require the use of other skills, such as Burglary or Stealth. Anyone exposed to these documents gets an Alertness or Scholarship roll to spot the deception; the difficulty is equal to your roll to make the document. Likewise, your roll is also the difficulty for any Investigation rolls to suss out your forgery.

Honest Lies:
Whenever incorporating a real, valuable piece of the truth (however marginally valuable it may be) into a lie, you gain a +2 on your efforts to pass off the untrue parts.

Pick Pocket:
Whether it's a simple bump-and grab or something more complicated, you're adept at getting people to pay attention to other things while you or an accomplice liberates their pockets of their contents. You may use the Deceit skill to perform pick-pocketing with no increases in difficulty. This includes the filching of small items from a desk or someplace similar. Targets of this action usually oppose with Alertness.

I Know Just the Guy:
When you're looking to gather some information from your network of contacts, you have unerring instincts for finding the right person, fast. When using the Gathering Information trapping, your efforts are at a +1 and are 1 time increment faster.

Corner of My Eye:
When successfully rolling Alertness passively to pick up on details, gain an additional 2 shifts. This reflects the ability to pick up on more pieces of information, but it does not improve the depth of that information (which would take things into the realm of Investigation).
 

Am I on the right track or is he significantly under or over powered?

 

Marci's Roller Skates [-0]
Description: A pair of pink and white rollerskates created as a gift to a powerful wizard's spoiled neice.
[-0] Purpose: To punish the person who wear's the skates.
[-0] It is what it is: A set of magical roller skates
[-0] Unbreakable. As an item of power, this item cannot be broken except with a magical ritual that opposes its nature.
[+2] Removing Skates: Before the skates can be taken off they first must be soaked for 2 hours in public fountain that is consecrated with a coin from the year and country the skates were made, 1972 America, and they need to be dried off with werebear fur.
[+1] One-Time Discount. A set of roller skates
[-2] Magical Skating: The rollerskates add +3 to athletics rolls when used to determine number of zones moved, and negates difficult terrain.
[-1] Skate Pro: The wearer recieves +2 to any performance check regarding advanced techniques, or tricks on roller skates.

The Eye of God [-3]
Description: An eye that when surgically implanted, can give true sight, seeing through all veils, and lies.
Musts: You must have an aspect related to your possession of this item.
[-0] Purpose: To see things for what they really are.
[-0] It is what it is: An eyeball that looks vaguely human.
[-0] Unbreakable. As an item of power, this item cannot be broken except with a magical ritual that opposes its nature.
[+1] One-Time Discount. An eye is easily concealed. Just keep it closed.
[-3] True Seeing: The owner receives a +5 bonus to perceive veils, shapeshifts, and glamours.
[-1] Added Insight: Gives a +2 bonus to empathy when trying to discern the truth.

The Staff of Phibus [-3]
Description: A powerful staff once belonging to an ancient but powerful politician and buissnessman. A man who was said to at one time own all the farms in the world, but that was a myth, or was it?
Musts: You must have an aspect related to your possession of this item.
[-0] Purpose: The staff is known for it's accelerated growing properties, and for spiritual enhancement.
[-0] It is what it is: A six foot tall staff made of a distinct but unique type of wood.
[-0] Unbreakable. As an item of power, this item cannot be broken except with a magical ritual that opposes its nature.
[+2] One-Time Discount. A staff is rather large and un-hideable.
[-4] Staff of Growth: All Plants in the zone the staff occupies and all adjacent zones increase rate of growth multiplied by the wielder's conviction score, and if concentrated on the rate of growth can increase by 20 times the wielder's conviction roll.
[-1] Nature Channel: Gives a +2 bonus to any spells used to interact with or enhance nature.

Considering that Powers - even from cursed items - come out of a player's Refresh total, I wonder if Dresden Files needs cursed items in the same way that they function in, say, Dungeons & Dragons (where cursed items are a consequence of reckless looting).

My thought was to use the cursed items as plot devices rather than loot.

Most of the good cursed items would be NPC territory, where a GM doesn't necessarily need to worry quite so much about Refresh spent on Powers.

For the most part, my intention was for the GM to use these items (as per a plot device). I am not unwilling to let PCs have them, but it was not my goal.

Are you intending these cursed items to have the consequences cancel out the advantages, such that they become -0 Refresh components of a character?

I didn't make them with refresh in mind, but if you were to stat them out, I would expect that they would have -0 Refresh or even positive refresh, if that was possible.

I noticed there wasn't a place to put true cursed items, and I wanted to share some of mine in order to get feed back and some other ideas for cool cursed items.
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Red Marble Sword
Description: A sword that chooses a wielder, for life, to carry out justice. The sword deals great misfortune to wielders other than its owner.

Musts: Aspect related to the possession of the item, and the pursuit of justice in all areas of life.

Purpose: To seek justice.

It is What It is: Long sword made of red marble.


Stats & Abilities:
Weapon: 5


Suggested Aspects:
Pseudo-Intelligence: The sword has a nature and goals it wishes to accomplish.

Chosen Owner: The sword chooses a wielder it finds worthy of its justice.

Bad Luck for Everyone but Me: If anyone other than the owner wields this sword, misfortune strikes them down (e.g. accidentally killing or maiming a loved one).

Inescapable Bond: The sword will always try to find its way back to its wielder by any means necessary.

Piqued Interest: The sword has the ability to look enticing or interesting to facilitate its travel back to its owner.

Only Death will Separate Us: Even if the chosen wielder revokes his path of justice, the sword will stay with him, usually trying to cause his death, until his death or reclaimation of virtue.

No Deed To Small: The wielder must always strive to be good (i.e. robbing a bank and snubbing a beggar are both "bad" in the sword's eyes, albeit varying in magnitude). If the wielder accumulates these "bad" actions, he must cleanse himself through an appropriate religious ritual or "good" act.

Unbreakable: This item cannot be broken except with a magical ritual that opposes its nature.
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Panda Mask
Description: A hollowed-out panda head made, for his new ruler, by a spiteful Chinese warlord after being conquered.

Purpose: To humiliate the wearer.

It is What It Is: A mask made from a panda's head.


Stats & Abilities:
Fire Resistance: The wearer gains Armor:2 against fire attacks.

Humiliated: Social attacks against the wearer are treated as Weapon:2.


Suggested Aspects:
Audience Request: The mask forces the user to perform tasks requested by any audience.

Sad Clown: The wearer always seems to be a good mood no matter the situation.

It Wasn't So Bad: If the wearer manages to remove the mask, they will inexplicably feel the urge to wear it again.

Easy for You, Not for Me: The wearer needs an extreme amount of discipline to remove the mask for themselves. On the other hand, other people can remove it easily.

Not so Resistant After All: The mask can be destroyed after being burned for an extended amount of time.
_____________________________________________
Hatred's Necktie
Description: After discovering an infidelity, a witch enchanted her husband's necktie. He was veiled with the town's most hate inducing form, and was hunted down before arriving at his mistresses' home.

Musts: Not already have a veil.

Purpose: To create a veil over the wearer that represents something hated by the viewer.

It is What It Is: A necktie.


Suggested Aspects:
Dapper Hatred: Whatever form the wearer appears to be in will always have a necktie on.

Loosened by Death: Once tied, the necktie cannot be loosened until the wearer dies.

Forgiveness is Your Only Refuge: Someone must feel true forgiveness to cut off the necktie.

Stain Proof: The necktie is always immaculately clean, even after being soaked in blood.

Oh God What Have We Done: The necktie loosens itself upon death and the veil disappears.

Piqued Interest: The necktie looks enticing, even next to a dead body.

The Eye of God [-4]
Description: An eye that when surgically implanted, can give true sight, seeing through all veils, and lies.
Musts: You must have an aspect related to your possession of this item.
[-0] Purpose: To see things for what they really are.
[-0] It is what it is: An eyeball that looks vaguely human.
[-0] Unbreakable. As an item of power, this item cannot be broken except with a magical ritual that opposes its nature.
[+1] One-Time Discount. An eye is easily concealed. Just keep it closed.
[-2] True Seeing: The ability to see through all veils, shapeshifts, and glamours.
[-3] Godly Insight: Gives a +6 bonus to Empathy when trying to discern the truth.

Everyone thank you for the help. I guess I still have a few questions about cursed items. I come from a DnD background, where cursed items are rather common, and I was wondering how cursed items compare and contrast with items of power.