Wpoison
"Wpoison is a free tool that can be used to help reduce the problem of bulk junk e-mail on the Internet in general, and at sites using Wpoison in particular... In the case of the Wpoison CGI program, the dynamic content that is generated each time the program is 'visited' (by a web browser, or by a web-scanning robot program) is just a list of randomized bogus e-mail addresses, together with a list of randomized web hyper-links."
