Mel gave you the instructions for how to set it up... but dear reader, we're going to go in-depth into the features of using MobileMe's Find My iPhone to see how well it works in locating and securing your phone from a remote location -- including performing a voluntary wipe.
Locating where your phone is via map
When you bring up the Find My iPhone page in MobileMe, the first thing you will see is a map giving the approximate location of your phone. As indicated above, my phone is somewhere inside of my apartment. Because the map is powered by Google, you can toggle it among plain map, satellite, and hybrid views of the location. However, the feature won't give off an exact address. So, if you happened to leave your phone inside of a shopping center complex, you'll still have to visit each store to track down the phone.
Read on for more into Find My iPhone's features ...
Display a Message/Play a Sound
For this part of the test, I activated the feature that will leave a message on your iPhone in case a good Samaritan picks it up, and also gives you the option to play a sound if you think the iPhone is still in your house.
My condo is about 830 square feet, with my desk tucked into the corner of the dining room. I shoved my phone deep into a basket of laundry on the other side of the place and turned on message/sound option. The "ping," which sounds more like a radar signal, was nice and clear even on the other side of the condo. The second location I hid the phone was a storage container inside my bedroom closet. I couldn't hear the phone from my desk or in the hall, but once I opened the bedroom door, I could hear the phone. The mileage you'll get from the "pings" will vary based off how many walls and layers of soundproofing are between you and the phone, but the feature works well enough that you shouldn't have a problem using the sound feature to find your phone.
The message side of the feature is pretty straightforward, and you can customize it however you want. Just be wary that if your phone is in public, someone may be able to get ahold of your phone number if you choose to have it displayed. Of course, if you're a parent and have control over a kid's iPhone or iPod Touch, it's a fantastic method of leaving them notes to do chores by!
For the sake of science, I also tested out the Remote Wipe feature, since there was a fresh backup of my iPhone due to the 3.0 install. Once I clicked the button, I got a request asking me if I was sure I wanted to completely wipe my phone. After acknowledging it, I sat back to wait.
So, what will you see if you're a naughty little person who has not only stolen my iPhone, but has figured out the passcode to unlock it? Well, suddenly, the screen will go black in your hands and the Apple logo will appear. Congratulations, you now have a very expensive brick with the Apple logo on it. Enjoy!
On my end, the iPhone suddenly disappeared from the MobileMe map, replaced with the words "Find My iPhone has been disabled because a wipe request is pending." I also got an e-mail to my MobileMe account informing me of my impending wipe, that it would take up to two hours, and that the process could not be reversed. That aspect is very true. I tried hooking my phone up to iTunes after the wipe started, and it did not stop it. So, I settled in to see how long it would take to wipe the phone. That aspect of the experiment failed, since I fell asleep while waiting for the phone to be wiped. What I did see when I woke up was a request for the iPhone to be hooked into iTunes. When I did that, the phone activated and went back to the default home screen. From there, all I needed to do was restore my iPhone using my backup in iTunes.
iPod touch and More
For those of you who have the iPod touch, fellow TUAW blogger Robert Palmer says that all of the Find My iPhone features work just fine with both first and second generation touches. The only thing that the first generation touch lacks is the ability to hear the "ping" sounds.
Michael Jones also informed me that he was able to set up more than one iPhone under his MobileMe account, so he could track both at the same time. He also lamented that, because he couldn't access www.me.com from the iPhone, he couldn't use his phone to track the other registered phone if need be. It's actually a very good idea and, who knows, a free app may come down the pipeline to address this need. But, other than that, Find My iPhone is a service that works extremely well and makes the MobileMe service itself a lot more attractive.