I had my iPhone stolen from me while I was at the gym. my locker was broken into. I had "find my iPhone" enabled. I quickly logged into my mobile me account using the gym managers computer, and was able to track the phone via GPS and google maps. I called the cops, told them where it was. I could actually watch the phone travel down the streets, going into stores, then go to the local bus terminal. I was on the phone with the cops telling them what I was seeing, street names etc. then all of the sudden the cop says "okay, we have an officer on foot pursuit" and then there was a struggle, and they arrested the guy right while I was on the phone with them. They said the guy took off running and they chased, tackled him, and he ended up in hospital. I got my phone back, my wallet and my coat, which he also stole, and tried to ditch while running. Couldn't be happier with the tracking of the iPhone. the cops all were enabling "find my iPhone" on their personal phones while I was making my statement, haha.
I wrote a long letter to apple explaining exactly what happened, but never heard back.
I was totally amazed at how the whole thing came together, and the police acted so quick, and caught the guy. They threw the book at the scum bag too. he was known to the police, and had no fixed address. basically a career their. apparently still in jail now too. This took place last winter.
edited to add: When I got the phone back about 20 minutes after the arrest it had only 1% battery left, then died before I could even turn it on.