Big Bang Theory Flash Mob

I am a huge fan of the show Big Bang Theory. It seems the actors on the show have a sense of fun away from their scripts as well. Watch the following flash mob that Kaley Cuoco (Penny in the show) organised and got her sister to choreograph. They sprang it on the audience during filming in November 2012 - and surprised showrunners Chuck Lorre, Bill Prady and Steve Molaro (if you're a fellow fan make sure you watch all the way to the end).