Groupme, the little group messaging service that made a bit of a splash at Google I/O, turns 3.0 today. There are some shiny new features on board, including a simpler way to exchange private messages and "Questions" for sparking conversations when you're not sure who to talk to. But, the big news -- Groupme 3.0 is now platform and nation agnostic. With the latest update, the service will be available in 90 countries and add Windows Phone 7 to its list of supported OSes, alongside iPhone, Bl
