As usual i phone is at their best.Check out one of the amazing application introduced by i phone. This is the best application to find the i phone .This application is default in the ios5 and forward but ios 3 or 4 users you don’t need to worry you can download this application by cydia by adding sources as further. I will tell u how to use the built in application of find my i phone .
1. First connect to the i cloud from settings then on the i phone icon
2. Now you can download the application from apple store.
3. open the application and sign in using apple id and pass code.
4. when u logged in the application u can see the location
5.you can also perform the function from this application like u can lock the i phone and wipe out your personal data.
This application can trace the iphone if gprs or wifi is active on that iphone or if is not connected to net any time he will connect the location will mailed to id so u can trace that.