Penn & Teller have a show on Showtime called Bullshit, where they debunk various things which people believe. I’ve got them on Netflix, and the first disk of season one is in my player now. During their ripping of “alternative medicine,” they convinced some people in a mall to put snails on their faces as a means of reducing wrinkles and stress. Ah, placebo effect!
I was going to link to a post someone had with a few dozen episodes of the show that were available on Google Video, but apparently the copyright police got to them. So, rent ’em if you want to see ’em (or get Showtime, but that seems a bit excessive).