Behold! The latest craze to reach the Otaku population, "Caramelldansen"!
I don't know how this started but suddenly I was seeing this in a lot of people's avatars in the Animesuki forums. I didn't even recognise the dance was from the OP of an adult visual novel game named "Popotan" that I watched long ago during the 56k days.
Apparently part of the OP animation was extracted and the remix version of a Swedish song named "Caramelldansen" was attached to it. Then it just spread with many variations. The above version uses characters from Code Geass (I actually wanted to post the one where Lelouch gets smacked by C.C. for not doing the dance). Original version can be found on Youtube.
Cute song, cute animation but I haven't been "infected" yet unlike the time when I watched Loituma Girl. Now a Doujin group is actually selling a variation of this clip in Akiba, "Haru-Uma" featuring none other than Suzumiya Haruhi for 367 Yen (US$4) according to Akibablog (NSFW).
There's a market for everything eh? Even keyrings that simulate bubble wrapping...