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.)