Spotted on John Gruber’s blog.

At first I didn’t notice what was happening until half way through. I had to go back and rewatch it. But then I was laughing for five minutes straight. It still makes me laugh now, even after watching it for probably my tenth time.

A higher quality version is available at their site. There are also others available. Dynasty, Golden Girls, Designing Women, and Cheers, I thought were also well done. The remaining were a little more mature or risqué, and IMHO not quite as funny.