I think this may fall into the "chocolate covered broccoli" thing that was mentioned but I've always thought this would be a good idea for studying: make a fun turned based RPG that asks you study questions whenever you attack or defend and give you a small boost if you answer correctly.

It would be cool as a web based RPG you could play from anywhere, or an extension to Moodle (http://moodle.org).

I could ramble on and on about the ideas I've had for this but I'll cut myself off here.