It shouldn't be too hard to create an enchanted item that serves as an 'external hard drive' for your mind. The problem would be the CPU. Intelligence is hard to come by. In the Dresdenverse, few creatures have an intelligence to match a humans. (Maybe the Sidhe, Dragons, and other Supernatural Heavyweights, but even Bob, as spirit of intellect, is lacking in some fundamental ways)
It would be impossible to create an intelligent construct, and using an existing intelligence is out of the question (or you might as well have Bob). However you could, theoretically, partition a part of your own intelligence into an external vessel. This would be like creating a ghost of yourself, or leaving a part of your soul behind. It would not be as efficient as Bob, since you're human, but it could work.
The best option I can think of though is a bit different. This returns to the original question of an internal archive. Instead of having a perfect-recall ability, imagine having something like Lash living in your head. Except, instead of a seductive devil, it's your own mental librarian. Partition a part of your own mind to a "mental library" and a connected part of your mind and soul to your "mental librarian." Or internalize an external Spirit (sort of like Demonic Co-Pilot). This would cost at least -2 refresh, and would probably have additional costs when using.
An advance on this is a Lessor Archive. Maybe a curse or enchantment passed from teacher to student. The lessor archive would store all the knowledge stored by predecessors in their own mental libraries. It would probably cost -2 refresh for each predecessor (or something like that) but it would allow the sort of "before your time" knowledge Bob gives to Harry.
As for using The Sight to store information... That's dangerous at best, unreliable at worst. Since The Sight shows you the True Nature of things, reading a reference book with The Sight means you'll remember more than just the letters and words. Its possible that viewing instructions to a ritual with The Sight will show you the inner workings of the magic behind the ritual, or reading a demon's name ... Anyway, there's also the issue of things shown by the True Nature which might could easily distract from the information you want to see (in a way not to similar to how a Somebody Else's Problem field can distract you from the spaceship in the parking lot).
It might, however, be possible to create a sort of manual that can only be understood through The Sight. That is to say, something with a true nature predicted an manipulated so that the entirety of what one sees with The Sight is what you intend for them to See. It would probably take a greater genius to figure out how to do this, but it'd make for an interesting plot device.
