Suwappu is a range of toys and an augmented reality concept from Dentsu London. You can read more about them here http://www.dentsulondon.com/blog/2011/04/05/introducing-suwappu/ and see more images here http://www.flickr.com/photos/dentsulondon/sets/72157624052479002/
Basically each toy has swappable top and bottom parts.. the colouring/patterns on each part registers as a marker, and your handheld device(video seems to indicate ios. android and others should be possible too)translates and shows you relevant graphics and animation.. and tweets :)
watch the video below to see how it works..
its very experimental right now, not sure if the AR part is restricted to just the characters.. or includes some of the other props as well..