Bing We're In
Are you one of the few out there who thought Latitude was, like, totally awesome, but your heart lies with the boys at Redmond? Well, rejoice Bing fans, because We're In is the location-based social network you've been waiting for. At its most basic, the app lets you share your location with friends, find contacts on a map, and update your status -- great for seeing who is around and organizing outings. But, We're In has one unique feature that's actually quite ingenious, location sharing is time limited. You choose who to share GPS data with and for how long. Once the invite expires -- poof! No more tracking. A few more details and the download link can be found at the source.