Had a rather long conversation with Kirsten on the weekend as to why we don't already have socially interactive robots everywhere. Kirsten being the artist she is, was focusing on the emotive and social aspects of robotics. I saw the dancing Keepon quite some time ago, and came across it again this morning in my RSS feeds.
The dancing (shown below) is kind of neat when you consider that the movements aren't preprogrammed. Rather there's an analysis of the music and a response in kind that we interpret in a meaningful way.
Keepon itself is a little research robot built to help understand attention and focus exchange with humans. It's somewhat comical that our brains are wired to "understand" what two fluffy balls with three dots is focusing on.