A mobile phone tracking service is being launched in the UK this week, reports The Daily Telegraph.
The service allows friends and family to find out where you are, but only if you want them to.
The technology delivers a map to the enquirer's mobile phone, giving the location to the nearest 100 metres, reports the Telegraph.
If someone has already agreed to be tracked, they have the option to be made invisible for as long as they want.
Users will be able to register on the Social Network Integrated Friend Finder (SNIFF) via social networking sites Facebook, Bebo and MySpace.
Each searching text will cost 50p. The service provider Useful Networks hopes hundreds of thousands of people will sign up.
The service has been running in Sweden for several months.