Purdue Beat Society.
http://web.ics.purdue.edu/~puraves/
I haven't been to one of these in a good while, so I don't even know if it's still going on. The last one I went to was ok, but by no means a rave.
Bloomington has a nice party scene, and a few raves throughout the year, and Indianapolis... don't have any. They have some good clubs though.
