[Air-l] Query: surveillance

Hi Folks, I'm trying to track down a fascinating web site I came across a while back devoted to a dating service that worked via cell phone: the idea was to allow eligble singles to know when they were in the vicinity of each other. If they subscribed to the service they would be alerted when other members were nearby so they could call one another "spontaneously" for a cup of coffee, etc. I haven't been able to find this service online, and just thought I'd check to see if anyone might have any leads. This is for work I'm doing on lateral surveillance/mutual monitoring. Thanks so much! Mark