ChicagoCrime.org is a free database of criminal activity reported in Chicago. It uses Google's map function to display "where bad things happen."

For example, here's a map of arrests for possession of crack cocaine. You can search for crimes by date, location, type, or more specific criteria, such as misdeeds occurring within bowling alleys. Described as the "Chicago police blotter on crack," the database is available as a customizeable RSS feed, so that you too can be constantly scared out of your wits by things you'd rather not know about.