Christina Mercando and I made an app for Lollapalooza that learns about your tastes to recommend bands you would enjoy at the festival. We entered the application in the HackLolla competition and were awarded the Grand Prize, making LollapaYOUza the official fan app of Lollapalooza 2012.
You can give the app a spin at http://lollapaYOUza.com. We also made a funny video to promote the app. I hope it makes you smile: