Kinetically charged, wrist mounted porn viewing device
That has got to be the closest thing to perpetual motion/energy yet - if they can use some of the charge to 'provide electrical stimulation' then the cycle will be complete.
The US Patent and Trademark Office has published a patent application that juices rumors Apple is working on a bit of wrist-wearable kit that hardware hypothesizers have dubbed the "iWatch". "Bi-stable Spring with Flexible Display" was revealed in the USPTO's weekly Thursday-morning application dump, and describes a snap-on …
I think people are giving the iWatch too much hype. The concept is merely for an iPhone/Pad companion device. You'll be able to show pretty pictures (accessorize!), get updates (walking directions/bus times/passbook/texts/caller id/etc) and control the music player. It could potentially also be used for games, but this is a companion device that could prove to be useful, like an Apple TV, not a core product.