The Smithsonian Institution's National Museum of Natural History is adding a T. rex to their collections, and to celebrate it, they've had Ray Troll and The Ratfish Wranglers record a song that they're calling "National Rex." What they need is a dance that goes along with it - a T. Rex Two-Step, if you will.

The first step, obviously, is to use your arms as little as possible. Make up a dance, take a 30-second video, upload it to YouTube, and email the link to You can also keep your eyes on the hashtag #rexstep on twitter.

More information, instructions for entering the contest, and a link to hear the song all at the NMNH website.

(h/t Brian Switek)