Via Wired: Gadget Lab and TUAW.Nothing more than an animated .gif file. When I downloaded into Animation Shoptm, it turned out to be just four frames! And less than 17k. On the webpage at the link below it is freakin' huge!
Pointless? Yes, of course. But oh so cool!
Point your iPhone browser to this location: Rock Me!
Suppose you could try that with your non-iPhone cellphone too, if it is interwebs capable.
Got a video iPod? Got one for download for you too: iScortch
BTW - I am not an iPhone owner. Got much better things to spend 0.6 of a C-note on.