Beginner C project

I've been studying C for a couple months now, and now I want to start on a small project that'll keep me busy for a few weeks or so. What should I start on?

A Roguelike is a damn good idea. You might want to look into libtcod for console support, especially if you're doing development under Windows. Anyway though I second the Roguelike idea, it'll teach you a hell of a lot.