i do not believe you can trace it unless you have certain apps installed such as the one parents use to track children. your phone provider can probably give you an estimatated area.. more detailed if you have wifi or gps on.
however, this assumes that the phone is both on and that it has your sim card or is a cdma phone. if the phone has a sim card slot, someone else can just pop their own in and have off with your brand new phone.
call up your phone provider and see if they can do anything for you. i'd be worried about the battery holding up though as normally you wont get more than 2 days maximum out of standby with nothing running.