Hello, I have tried to use GPS without WiFi and without SIM card, but never worked. I have coded a program based on example 'LocateMe', that can be downloaded at Apple Developer page: http://developer.apple.com/iphone/library/samplecode/LocateMe/index.html I'm only want coordinates and speed, not maps or something. Instance method locationManager:didFailWithError: always returns me kCLErrorLocationUnknown. I have executed the program in opened sky for about ten minutes, and always returns kCLErrorLocationUnknown. Is iPhone blocked the use of GPS without SIM card? Anyone can help me? Thank You. PD: Sorry for my poor english.