Robot 'Gangnam Style'

When Vietnamese toymaker Tosy's mRobo was first shown off at last year's CES, introduced by none other than Justin Bieber, its song-and-dance routine was underwhelming.

Tosy went back to work on the entertainer droid, giving it more actuators, moves by choreographer Derek Hough, and a tune to dance to -- something called "Gangnam Style," which you've probably never heard of.