Location based social networks are the current darling of social media. Foursquare is leading the way with what seems like a new Fourtune 500 endorsement each week. It is unclear where all these tools will lead us. Foursquare, Gowalla, Whrrl, and even MyTown are getting a lot of attention and a lot of businesses, big and small, are experimenting.So let’s take a moment and capture what all has been done with these tools to date. How are big brands testing the space? What are brick and mortars playing with? Nothing earth shattering here, but the more businesses experiment in the space, the more we all learn.