Anyone used to be able to send a postcard to a U.S. service member by addressing it to "Any Service Member." Now a name is required to send a physical letter. That's where the Gratefulapp mashup comes in. It broadcasts your message via Twitter to troops--or anyone else who checks out its rotating front page.
Yammer, a microblogging-for-business site and winner of the top prize at the recent TechCrunch50 conference, has released an API to allow developers to build their own applications around the service (Yammer API profile). Created by the people behind genealogy site Geni, Yammer has taken the tried and tested Twitter model, which asks users to answer the question "What are you doing?" in 140 characters or less, and adapted it for businesses, turning the question into "What are you working on?"