Found on the Office Tips and Hints Blog…
I’ve mentioned the Museum of Hoaxes before, and most people are familiar with Snopes.com (the Urban Legends Reference Pages). I just learned about a similar site that specifically tries to debunk chain letters:
BreakTheChain.org is your source for common-sense evaluations of e-mail chain letters, helpful tips and advice.
There are dozens of chain letters that are explained on the site. You can view the What’s New page (it doesn’t seem to be updated that often) as well as the forums.