Lost or stolen, we don't know, but gone for sure.

I heard that with these modern phone, it was possible to locate them, even when turned off

We contacted the phone company, they said they don't provide this kind of service. Any idea how to do (and if it's possible anyway ?)

I understand it is possible if you had the correct software installed incase of such an event.

Wouldnt know how to do it otherwise.

if you subscribe to mobile me service, it can locate your phone. otherwise, if you had tracking software installed, you could find it, but you would know if you did, since these apps are not free so you would have paid for it and installed it yourself. if not, then it is gone.

I realise the horse has already bolted, but, for future reference, iProtect is a nice app generally that also secretly sends an SMS to a number of your choosing in the event that someone changes the SIM card. The SMS contains the phone number of the SIM card in the phone. Useful for tracking down the culprit. Available from Cydia, so you need to be jailbroken.

When you plug your iPhone on your computer, I know iTune can identify your phone, I mean not your tel number, but the serial number of your phone. And without iTune there is a lot of things you can't do with your iPhone. I guess Apple should have a way to do something but I tried to call their hotline, nobody answers, maybe because it's Sunday ...I'll try again tomorrow

When you plug your iPhone on your computer, I know iTune can identify your phone, I mean not your tel number, but the serial number of your phone. And without iTune there is a lot of things you can't do with your iPhone. I guess Apple should have a way to do something but I tried to call their hotline, nobody answers, maybe because it's Sunday ...I'll try again tomorrow

Key in the following on any phone and it gives you the serial number of the phone. *#06#

You need to do this before your phone is lost stolen etc.

With this serial certain organisations can switch on the phone remotely without any light or sound emissions. The phone then acts as a microphone. It can then also be located via trianglation. All this is possible if the battery is on. Doesnt matter who's sim card is in it.

Telecommunication companies can also send a signal to kill the phone. It basically fries the circuits making a stolen phone inoperatable and worthless to the thief