Mailinator Spam Map
Mailinator(tm) is a service that gives you free, disposable email anytime, anywhere. No need to ever sign up. Send first – come to the site later. Mailboxes are created when email arrives for them (see the FAQ for more information).
Mailinator is about saving you from spam. But in the process it ends up getting plenty of its own (averaging over a million emails a day!). This map shows (in semi-realtime) ip addresses that are currently sending the most spam to Mailinator.
Found via http://del.icio.us/popular/