You can try installing this Lookout: http://market.android.com/details?id=com.lookout from the Google Play Store website. Once it says that it's installed, go to the Lookout website and create an account, etc. From there you should be able to find the phone.
Sent from my rooted, debloated, deodexed Sinclair ZX-80 running CM -0.001 using Tapatalk 2
I also recommend LookOut Mobile. It is free and works well. The other option is to call your service provider. They may be able to give you a rough idea of the location.