I lost my iphone about 4 months ago. I tried calling and texting the phone to offer a reward (I would have bought them a new one just for finding mine) but they soon either turned off the phone or pulled the SIM. After that, I got online with AT&T and reported it lost/stolen which suspends your phone service. Be sure and get online and reset any passwords that you had set up (IMAP/POP email, iTunes, Facebook) so the theif can’t access it. After that, there is really nothing you can do. Bummer, I know.