Snopes (www.snopes.com) is a web site
titled "Urban Legends Reference Pages", which sums it up quite nicely. The upkeep of this site is a hobby of Barbara and David Mikkelson. It contains lots of information about urban legend
and the like. If you ever wonder whether this or that story you heard is true, this would be a good starting point
The site is organised into different categories (like history, computers, crime, etc). A search field lets you find specific stories, and a handy randomizer button makes for general slobbing around the site (sounds familiar, somehow...). Each article is marked with a color indicating truthfullness: Green for true, Red for false and Yellow for undecided/almost.
Snopes is my second favorite web site. It is a large database of articles, with lots of links to follow up stories of particular interest. I have spent countless hours on the site, finding incredible nuggets of information. It is definitely worth a visit if you haven't already seen it.