You can use Plan B by Lookout. That is for finding your phone when you don't have the regular Lookout Mobile Security installed on it. It worked for me after my daughter lost her phone, through the use of a computer we found it. It's free, and it works. After you find your phone, I'd suggest installing Lookout on it. I swear by it.
Aw that's Know Fun..Well since some have give you some good advice already have you Suspended your Line! it would be a good thing to do. So the Thief that is Enjoying it for Know. Won't for Long..b33