Brightkite location-based social networking in Beta

On the topic of location-based social networking, have you heard of Brightkite yet? It's one of those cool, Twitter-like social networking apps that takes advantage of location-based tagging. The service enables users to meet people and discover others that share an interest in places that you visit. BrightKite is currently in an invite-only Beta. I was interesting in seeing that the company is setup in Denver in a trendy loft and has recently received some funding - looks like some competition for Spatial Networking perhaps! Indeed social networking is hot, add to the mix a mobile, location- aware application and you have a cool idea. You have to wonder though, is there room in this space for more players or will Twitter and Jaiku rule? Also, like map mashups, how will these services be monetized?