The University of South Florida is hosting a social media scavenger hunt for Homecoming Week starting October 17. The students will access Twitter, Facebook, Tumblr, YouTube, and Foursquare in order to virtually check-in to various physical locations on campus. There will be hundreds of prizes including t-shirts, hats, and a HP printer, and the grand prize winner will receive a iPod Touch. I'm thinking other universities might want to do something similar. You can find more info here.