You've probably already heard about it, I had not. Until it appeared in a newspaper online. Made coffee land on my keyboard as I was drinking some and did not know what to expect.
Here it is, but don't drink anything while watching if you've never heard of the "harlem shake" before: http://www.youtube.com/watch?v=tVUB2_CQ6Bk
It's not the greatest thing I've ever seen but it certainly was unexpected.