Wanted to try this - flying to Guernsey and back today.
It's an iPhone 4, and the scanning typically goes from top left to
bottom right so moving objects lean to the left.
Essentially any electronic shutter camera (i.e. not an SLR like mechanical shutter) will give these effects. Wikipedia has some good articles here:
For those who want to try this out, just point your simple electronic shutter camera at an object moving parallel to you, preferably fast, and take the photo. The faster the relative speed between you, the more the distortion. Rotating objects go really wierd!