I've been using the Milna application on my phone for a couple of days. This is a "social networking" application with a bit of a twist - it is location based and, requires that you post what you want to do. Users near you (the distance is configurable, but you'd want to keep it really near you) can join in and, together you'd have a blast. Good fun really ! You don't necessarily have to be on any specific network or, be "friends" with anyone. Just make a wish and perhaps you'd have folks joining in. They need to be using the app though. So, you should ideally keep pointing out the website to them.

And, as I was thinking, the app could be a good fit to organize a flash mob ;) or, a party or, a jamming session. Or, anything that can have you making new acquaintances and perhaps striking up a friendship. Runa pointed out the small concern that it might also be used for stalking, but I guess that is something the app developers have already thought about. The app (or, if there is a custom web service ever) can also be used as private instances. Think of a private Milna server/instance for your team and you could perhaps have a "Chatter" like thing going.

For me the current downside is the lack of users near me using the app. That needs to change.