It turns out only 15 percent of all updates to Wikipedia English come from unregistered users, but they can sure wreak some havoc. Recently, someone added the phrase "grandma sucks" to the entry for "Grandparent." Shame on whoever took to anonymous grandparent bashing!
But the Wikipedia Recent Changes Map, shows where every unregistered user is editing from in real time. You can watch the titles of Wikipedia entries that have just been altered on a map of the world, or you can watch a quickly moving list of items scroll by. By clicking on the page name, you can also view the other edits each user has made. The grandma hater, for example, apparently had a number of qualms with the Wikipedia entry on "U.S. Temperature Extremes" back in December.