Apparently "flash mob" dances are still a 'thing', because the cast and crew of "The Big Bang Theory" recently did one to Carly Rae Jepsen's "Call Me Maybe".

 

 

--It was all organized by Kaley Cuoco, who plays Penny.  She got her sister to choreograph it, and about 40 or 50 people surprised the producers by busting it out during a live taping a few weeks ago.

 

 

--CBS posted the video on YouTube yesterday.  (--Search for "The Big Bang Theory Flash Mob."  The music starts at :13, and the cast joins in at :33.)