Track your friends by SMS (via GPS)

You’ll have more fun with GPS devices from now on: GPS.pi is a new way
to track your friends’ position and movements over a map. The service is supposed to function by coupling a GPS receiver with a PPCPE device, but it will work with a cell-phone aswell. GPS.pi needs e-mails or SMSes with the exact location of persons to be tracked, and it is really useful on trips and even long journeys.