http://www.spamhelp.org/harvesterkiller/

From the page “This page shows a 100 randomly generated email addresses. Email harvesters (also known as spambots) will crawl this page and store all of these hundred bogus email addresses in a database, and follow the link at the bottom of the page, filling them up with more invalid email addresses as they go along. They eventually end up in an infinite loop, and thousands of randomly generated email addresses before the spammer realises what’s happening.”