I've been browsing sourceforge quite a bit, looking for existing projects to work on. I have just submitted my first patch, a bugfix for
Inkscape. Woohoo! I agree, it probably makes more sense to contribute to something that already exists. I don't have any interest in working on games; I waste enough time playing them as it is
Thanks to everyone for the suggestions though! I'd love to hear more, but I think I may be able to keep myself occupied by improving existing software. It's nice to finally, in some small way, join the ranks of open-source programmers. Feels good to give back something.