WikiTribune - Evidence based journalism, from the founder of Wikipedia
Snaptivity - Real-time photo sharing with the world nearby
Data Dashboard by Wikimedia Foundation - Compiled data of the Worlds busiest public site
Flashgap - Time-delayed photo-sharing app of last night's embarrassment
Neighborhoods.nyc - Hyper-local alerts targeted by NYC neighborhood
WiFi Map - A crowdsourced list of routers and passwords