I recently received an e-mail sent to dozens of people about a deadly gang initiation taking place in Albuquerque. Rather than pass on the paranoia, I checked out the rumor at Snopes, a one-stop shopping for affirming or debunking all kinds of hoaxes and urban legends. Once assured that the initiation is indeed a rumor that has also spread in places like Tennessee, Louisiana and New Jersey, I got sucked in to a couple of other debunked myths.
I can't remember when I first heard that "Ring Around the Rosie" is based on the Black Death, but guess what? It's not true. I also read up on a seasonal myth I hadn't heard before, that "The Twelve Days of Christmas" was a catechism code for persecuted Catholics in England. There's also an entry about the mysterious origins of today's holiday: Boxing Day.
Urban legends and hoaxes have always been around, but now with speed-of-light internet and email it seems that they're breeding at a prodigious rate. While there are many great books on the subject, none of them are timely enough when my aunt emails me an urgent message about a virus or hoax making the rounds. For up-to-the-minute information like that, Snopes has been an invaluable tool.
Another useful site for those gray areas and odd questions is The Straight Dope. The answers are well-researched and entertaining, while the questions are often things we've never thought to ask, or don't know how to ask. So at The Straight Dope you can find out if it's possible to survive on a diet of potatoes and milk (yes, with some oatmeal thrown in), what jake breaks are (a question I have on road trips on Old Pecos Trail), and why doesn't wood melt? Enough questions and answers to keep you informed about minutiae in perpetuity.