The iconic Sydney Opera House are running a Hackathon in Sydney over the weekend of Dec 7-8. With a first prize of $4000, this might just be a great way to spend a weekend. They’re making a heap of great data sets available including archival recordings and a huge 3-D spatial data set with a model of the Opera House both inside and out.
Check out the details on their site here. (By the way, even though they explicitly mention iOS and Android, I’ve checked and they’d love to have Windows/Windows Phone developers along).