Mobile Me's Find My iPhone is a wonderful (relatively) new feature which can help track down your iPhone if it is lost or stolen, but it is not foolproof, and it must be configured before you need it.

Q: "Is it true that Find My iPhone does not work if you have 3G turned off or lose your iPhone where there is no 3G service available (EDGE only)?"

A: False. Find My iPhone works with the original iPhone, which did not even have 3G or GPS capabilities, so it does work with EDGE. If you have a 3G-capable iPhone and disable the 3G (Settings > General > Enable 3G > OFF) to save battery life, "Find My iPhone" will continue to work.

Q: "Will find my iPhone work over WiFi?"

A: True... sort of... Maybe... Not really. In my home I have very little or no AT&T service (or Sprint, or Verizon, or any other cell provider). I do have WiFi all over the house, and Find My iPhone has never failed to help me locate my iPhone when it is "lost" in my house. In order to test it purely over Wi-Fi, I put the iPhone into Airplane Mode (meaning that both EDGE and 3G were both disabled) and enabled Wi-Fi. I asked "Find My iPhone" to locate my iPhone and was told that it was near Orlando, Florida. It was, in fact, in Ohio. I repeated the test and it came back with the same information. Later, I tried the "Wi-Fi only" test from my home, and Find My iPhone could not find my location at all.

However, even in Airplane + Wi-Fi mode I was able to use the "Display a Message" and "Remote Passcode Lock" features. So you may not be able to locate it on a map, but you still may be able to connect to it.

Proper setup is your first crucial step

All of this is a moot point if you don't have three crucial settings enabled on your iPhone. Without any one of these, Find My iPhone will not work.

1. Settings > General > Location Services has to be on (this one is obvious, right?)
2. Under Settings > Mail, Contacts, Calendars > (Your Mobile Me account), you must set "Find My iPhone" to ON. This is not enabled by default.
3. Under Settings > Mail, Contacts, Calendars > Fetch New Data, you must either enable Push OR have fetch set to Every 15 minutes, 30 minutes, or Hourly. If you disable Push and set Fetch to "Manually" Find My iPhone will not work.

The MobileMe Find my iPhone service certainly paid off for a Pittsburgh area man. The Pittsburgh Post-Gazette reports that police said the man was robbed at gunpoint in Shadyside (a neigborhood on the east side of Pittsburgh, home to an Apple Store) by two men who asked for his credit cards and the PIN numbers.

Police say he turned over his wallet, PIN numbers, and his iPhone. Later the man used his computer and MobileMe to find the location of the phone, and police located the crooks at a gas station. Officers recovered a pellet gun, stolen ID cards, credit cards and cash.

Three men have been charged in the incident with device fraud, conspiracy, receiving stolen property and possessing instruments of crime. 2 of the 3 are also being charged with robbery.

The victim, not identified by the police, is probably a happy guy, and will no doubt renew his MobileMe subscription when it comes up.

One caution. If something similar happens to you, don't go chasing the thieves by yourself. Confronting criminals is serious police work & nothing for the amateur sleuth to try.

[Via the Pittsburgh Post-Gazette and thanks to Sean for the tip]

We're not 100% convinced of the safety of his approach, but Kevin Miller's determination to recover his lost iPhone -- combined with the power of MobileMe's new Find My iPhone feature -- led him on a wild chase across Chicago, which he visited while he was attending a LEGO convention in nearby Wheeling, IL.

After leaving his phone in a bar, Kevin tried to get FMI working (via a friend's laptop & broadband adapter, ironically from Sprint; as Megan & Michael pointed out, you can't access the MobileMe page from the iPhone browser anyway) with no luck. The next morning, however, the phone began responding and Kevin's three-man team began the hunt. With laptop in hand and a succession of more and more specific location details, the guys began tracking down the errant phone.

We won't spoil the end of the story for you; Kevin's post is quite entertaining and worth a read. Still, once you do know how the plot turns out you may want to consider enlisting the police for a missing phone, rather than choosing to use their methods.

iPod touch users are finally getting a taste of what iPhone users have had since iPhone OS 2.2: Google Street View. iPhone 3.0 Software Update for iPod touch includes an update to the Maps application that enables Google Street View, and it works just like it does on the iPhone.

Additionally, the "Find my iPhone" feature is implemented as "Find my iPod touch" for iPod touch users. It works exactly like Megan described yesterday, but is perhaps less accurate than using the iPhone's built-in GPS. It'll at least get you close, so long as it's connected to a Wi-Fi network. If it is, you can send messages to the iPod touch and wipe its memory.

If you do send a message to an iPod touch that's turned off or not connected to a Wi-Fi network, the message is queued until it's on and connected.

Both features appear to work on both first- and second-generation iPod touch devices. As Megan mentioned, since the first-generation iPod touch lacks a speaker, it won't make the "ping" noise associated with Find my iPhone unless you have speakers plugged in. Perhaps less useful for finding it in the house, but still helpful if you left it on a table at the park.

Have you found an undocumented feature that the iPhone 3.0 Software Update for iPod touch provides? Let us know by tipping us, or leaving a comment.

Thanks, Harold, Ben, Rocky, and everyone who sent this in!

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 ...

With all the excitement about iPhone version 3.0, there isn't a lot of help on how to set up one of the most unique features of the upgrade, Find my iPhone.

If you're having trouble, here are the steps. First, the service has to be turned on. You do that in your iPhone settings. Under email accounts, select your MobileMe info. You'll get to a page that has an on/off switch for Find my iPhone. Turn it on.

After that, you must be in your MobileMe web page. Sign in. At first glance, you won't see anything. You have to click on the accounts icon, and you should see a Find my iPhone icon at the bottom of the account settings. You can then decide to find your iPhone on a map, send it a message, or remote wipe it. I found the map pretty accurate, as I have a metal roof on the house that plays hell with GPS and cell signals. I sent a test message. That worked fine, and I received an email confirmation that the message was sent to the phone. I didn't try the remote wipe. I've spent enough time today downloading and uploading iPhone software and data.

Note: Apple MobileMe servers are a bit spotty today. It took me a couple of tries to get into my account options.

Find my iPhone is a powerful new feature. I hope I never need to use it.

Here's what the icon looks like on the MobileMe page: