Snopes is a fantastic website that has gathered together a massive number of urban legends, hoaxes and scams and provides information on their validity and origins. Think of it as Mythbusters for the web.
Whenever a concerned acquaintance forwards me an email telling me that aspartame will kill me, or that Bill Gates will give me money or that I should stop using my microwave, the first thing I do is check for a known hoax on Snopes. I then email the link back to the sender, and ask them to consider checking the validity of emails before forwarding them on.
In terms of schooling, Snopes provides students with an informative and fun tool for learning skills of information literacy and critical thinking. Try gathering together a set of emails and get students to guess which might be hoaxes: then get them to use Snopes to see how they did. Discuss with them the reasons why such legends become ingrained and accepted as true, and how they can protect themselves from them. For older students, get them to consider the validity of Snopes itself: can they find other sources to verify or counter the claims made on the site? Finally, students might be asked to consider the philosophical questions of “Can we be sure of anything?” and “What is truth?”.
I think my favourite Snopes moment of all time was when I learned that, contrary to popular belief, Bobby McFerrin (the composer of “Don’t Worry, Be Happy”) had in fact not committed suicide. From that day, I have become much less believing in things I read and hear, especially on the web.