It’s true! The built-in compass can be used as a metal detector, allowing you to detect keys that are very close to the phone. Is this particularly useful? Probably not, but now you can rub your phone against people like a stud finder and perhaps make new friends when you search for their “keys.”
Some folks at HDblog.it shot some video of the app in action. Worth a look.
Umm, metal does not automatically mean magnetic. Call me on your G1 if it can detect Aluminum, Titanium, Copper…
Its a phone, not a tricorder.
Of course it won’t give the peformance or all of the features of a “real” metal detector, this is more of a “neat” little thign somebody did than a replacement for a real device.