I like playing around with magnetism when it comes to earth magic. Magnetic fields can induce an electrical current in metal, and that current can cause the metal to heat up and in extreme cases melt.
Example:
http://www.youtube.com/watch?v=d7DBS2Is0wsAlso, gravity doesn't have to mean pushing someone further down, but you could pretty much make him move in all directions. One of my characters (though he is a science mage, using a different elemental set) has a spell where he can do a sort of gravity tunnel that lets him sort of fall upwards to get up a building and things like that.
Then, as others said, there are all kinds of fun you can have with the element itself. Most buildings are made of some kind of stone. Do a spell that lets you become one with it and simply walk through a wall, without the need to break it down.
It all comes down to your characters style. I could see a metalbender style character, that is carrying a piece of metal everywhere and morphs it into all kinds of shapes to fit his needs. A lance that lashes out as an attack, a flat disk in front of you to clock, a chain to constrain someone and many many other things. I've actually had something like this plant as an IoP for a character (the metal takes the form of a bracer by default, and can be morphed from there).
