> Perhaps you could set up teams that could compete with each other through a series of programming challenges? You could find a local business who would sponsor a prize, or a restaurant that would offer a dinner for the winning team.

I like this idea. Through my experience in several student orgs, it seems that the best way to get people to stay involved is competition and prizes. Personally, I would much rather see students be self driven, but there's a hump of "oh I'm too busy to do this" (or something of the sort) that most students need to get over before taking a huge interest in it.