The image above was shot by Jason Mullins with his iPhone 4 on a flight from London to Guernsey. The weird black lines you can see are actually distorted, disconnected copies of the propeller blades, but this isn't a Photoshop hack; this was how the image came out of the phone.
Virtually all consumer grade digital cameras, including cell phones, do not take the picture instantly when you push the shutter button. Instead, they quickly scan over the
CCD CMOS sensor from the top left to the bottom right, like the electron beam in an old CRT television. This is called rolling shutter capture. This scanning process is fast, but sometimes it's not fast enough. If you angle the device just right and take pictures of fast moving or rotating objects, you can create all sorts of weird and funky distortion effects. You can see more like this in the rolling shutter Flickr group.
(Thanks to Jason for letting us reproduce his shot; he's put a few more pictures on Flickr from the same flight.)[Post updated to correct CCD vs. CMOS sensor used in the iPhone.]