Loosing any phone be it Android or not is never a nice experience, soon you’d simply realise you’ve lost a part of you, infact you will feel literally bereaved.
Those who lose their phone often times wonder how they can either track or block their stolen Android phone. Here’s the simplest answer and solution to the quest that I know.
It isn’t originally my post so am going to attach the source at the end of the post.
The EMI number is on the box the phone came in if you still have it and the best way to lock it and make it unusable is to call your carrier and tell them it was stolen once you do this it will be deactivated and if the person who stole it tries to activate it at the store they will know its stolen and then it will be returned to you. Also if the phone is stolen and it is an android powered phone. Log into your gmail account on a Pc and go to the play store from the play store download the app Plan B to your phone from lookout. The app will silently install to your phone turn on gps signal and then will email you the exact coordinates of the device to your email from there you can call the police and tell them where it is and they can go and get it for you.
Go to that link if its android powered and read the apps description and follow the steps this will only work if the phone is on and is currently connected to a network.
If the phone is not android powered contact your carrier and report it lost or stolen so you dont get charged with unexpected charges.
Good luck and hopefully your phone is android powered so you have a chance of getting it back.
Source: Yahoo! Answers