Imagine you are a woman at a party who spots a good looking fellow standing alone in a comer. Before working up the courage to talk to him, you whip out your mobile phone. A few clicks reveal his age and profession, links to his latest blog post and an amount of other personal information. To many, this sounds a nightmare. But to those building mobile social networks, it is heaven: linking virtual communities such as MySpace with the real world. The idea is not new, but so far such services have not gained much traction. They have to be able to pinpoint people in order to work, but satellite positioning does not work indoors.