With all the slowing-down and speeding-up of videos, I actually have no idea if this Mythbusters clip in which host Adam Savage demonstrates the effects of sulfur hexaflouride on his voice is real or not, but it is cool. I'm pretty sure it's real, unless wikipedia is somehow wrong (ha): [videoembed size="full_width" alignment="center"][/videoembed] Here's some hipster kid doing the same ...