Taking the iPhone 3GS on the subway will repeatedly get its compass all out of whack. It sits and spins in all directions. Eventually it produces this screen:
I don't know how the compass works in the phone. But I'd venture a guess that the big, giant electrified track might have something to do with the "Interference" referenced in the alert.
Fun stuff. Love the figure 8. Very classy.
Is that, like, a nautical thing?