I know this is a little late for Haiti but for future:
Something we do often at my school is run dances. The high school kids all think they're too cool for dances though so we decided to host the dances for grade 7 and 8 students from our associated elementary schools instead. We make thousands of dollars for each one!
Just book your tech crew (or whatever you call them at your school) and make sure they can hook in an ipod, set up a playlist, drop off tickets to the schools, go pick them up, and decorate your gym. It's never failed us yet and we've been doing them for 5 years now!
Good luck and hope this helps