There are definitely dating services working in this direction, at least for people with iPhones. I don't know if anybody is integrating with existing social n

There are definitely dating services working in this direction, at least for people with iPhones. I don't know if anybody is integrating with existing social networks though. I've seen iTryst Lite and datingDNA on the iPhone that take location into account when matching people. Not sure how much success they're having though. Adding onto existing dating brands would probably get more traction..