Flash Mob!

What's with all of the flash mob dances that have been popping up all over the world lately? I love them! How do you get to participate in one? I would totally do it, in fact, I'm trying to get my boss to let me put one together to promote our company intranet. We have a nice big cafeteria after all. Here's one with the Sound of Music. Pretty cool. One thing many of them have in common is that they often take place in train/subway stations. We don't really have those here. Here's another one, this one ON a train (moving, no less).