This is a video of former FBI agent and body language expert Joe Navarro explaining how we use non-verbal communication, and how to read some of the information people knowingly and unknowingly present. I learned a few things by watching it, but mostly because it was fifteen minutes long and if you can watch something for fifteen minutes and not take anything away from it, it was probably reality television. Of course the only real piece of body language you need to know is if we're both stripping naked as fast as we can, we're probably about to get, well...you know. "Ketchup and mustard all over ourselves." Don't forget the relish!
Keep going for the video, which concludes with some poker tells.
Thanks to Christopher C, who I'm pretty sure just winked at me.