Almost everyone else wrote webapps. We decided to try using Silverlight to gain the Microsoft prize money (you had to use MS tools to get the prize.) Now we're working on implementing it with Ruby on Rails and a Twitter UI. See our prototypes at http://www.backstagecasting.com/ & http://backstagecasting.qa-site.com/
Actually, the winner wasn't an iPhone app, it was "going to be" an iPhone app, meaning that was one avenue they pitched pursuing if they developed it further. It's just a flashcard memory game for contacts from LinkedIn. A clever, simple idea with a potential market. Check it out here http://www.learnthatname.com/
If you can't get your work done in the first 24 hours, work nights.