It's not everyday that you learn about the existence of a new musical device. Betty would like to share the one she learned about today with you!
It's called the Kaoss Pad and in this performance you can see Jonny Greenwood of Radiohead (in the yellow shirt) using it to great effect all through, but especially towards the end. It's basically a musical joystick. It is also a little bit like an iPod that is a musical instrument. You can Greenwood storing Thom Yorke's vocals in the device throughout the song, and then playing them back as if they were guitar loops towards the end. He even gets Yorke to harmonize with himself, all thanks to the Kaoss Pad. How fun would it be to just walk around a city all day collecting sounds with one of these!?
Also note that this is just a great performance of the song! Percussion, bass, vocals, and keys are locked and perfectly placed and layered over each other, and like all of the songs on Kid A, the timing of the lines is both unpredictable, strange, and totally patterened.