project honeypot

As we all know, those durned spambots are always harvesting email
addresses out of web sites. If you want to get in an argument, start
a debate about how to harvest-proof an email address on a web site with
a bunch of web masters about. It gets fierce fast.
Many a coding scheme/javascript/etc scheme has been proposed but...
Thus this project sounds worthy:
http://www.projecthoneypot.org

"Can any site add a Project Honey Pot spam trap?
Many can, but not all. Project Honey Pot addresses can be added to most websites that support dynamic content and scripting languages. To install honey pots on your site, you will need the authority to install executable programs on the server hosting your site (e.g., access to the cgi-bin directory). We currently offer direct support for websites built with PHP, Perl, mod_perl, ASP, Python, ColdFusion, and Movable Type (v.2.6+, you can get more information about our MT plugin here). We plan to add support for ASP.NET, JSP, and Zope soon. In addition, we are working on plugins for other content management software such as Blogger, as well as an API. We generally publish our script software under the GPL. If there's a solution we don't support, but you know how to make it work, drop us a line. We are always looking for ways to bring Project Honey Pot to more websites."

They claim the javascript obfuscation method is 100% effective.
I don't know. I've been using that for years and I'm not convinced it
is but I'm pretty sure it is a lot better than not using it.
http://www.projecthoneypot.org/how_to_avoid_spambots_3.php
I was not doing it exactly the way it is done here.