Imagine to be at a concert, how many people could be around you? well sonar ll track this and communicate could be easier and cooler. Sonar could also be used for meeting and business conferences, seems good for freelancers too, a good way to get into new people.
I'm looking forward to try it at a big event or in a crowded place.
http://api.sonar.me/ http://blog.sonar.me/