http://www.faqs.org/faqs/net-abuse-faq/harvest/
There are many ways in which spammers can get your email address. The
ones I know of are :# 1. From posts to UseNet with your email address.
Some chat clients on PCs behave similarily, so using IRC can cause
an email address to be given out to spammers.
Some sites use various tricks to extract a surfer's email address
from the web browser, sometimes without the surfer noticing it.
http://www.monkeys.com/wpoison/
and that new page will contain its own totally new set of bogus E-mail addresses