I recently lost my iPhone and had someone answer when I called bu they hung up immediately and won't answer anymore. I don't have any software installed on it like MobileMe or anything like that. AT&T said they couldn't help so am I shit out of luck or is there a way to trace it? Any advice is greatly appreciated.

Try ATT again. If you own the Cell they can track it you just have to get to a tech or supervisor that is willing to do it. They can triangulate it from the cell towers and also they can deactivate the SIM in it if nothing else.

Call ATT and give them you IMEI number. At the very least they can add the IMEI to a blacklist so that the phone can't be used on their network. This doesn't prevent it from being jailbroken and used elsewhere, but i doubt a petty thief would know how to do that.

ATT usually will not provide you the phone's location without police involvement which probably won't happen since a $300 phone would not justify the thousands in time it would take to pursue.

IF you didn't have one of those location aware services for finding a lost phone, you are probably out of luck. Sorry about the loss.

maybe if you have installed a gps program on it, or thru the provider