Been playing with Hudson recently, and I am impressed. Easy to setup and use (well, that is relative...) It even has a Chuck Norris plugin
The best way to get started with Hudson and PHP is Sebastian Bergmann's php-hudson-template, but there are also other good articles: Ladislav Prskavec's PHP and Hudson, and Goran Juric's Hudson on Debian Lenny.
I needed to get it running on Windows, so there were some additional hoops to jump through, such as some pear-installed tools hard-coding ./php.exe in .bat files, but almost everything else just works.
Update: Found some more articles, by Dave Gardner and Justin Palmer
Also, having more Windows troubles (though it could be something else) - can't get a build to succeed, even though all the tests are passing... in the end I modified some of the tools to always return zero. The real setup is on a Linux box anyway, and it all works fine there - except that graphs use some funny-looking fonts (fonts were just missing, yum installing a few font collections and restarting hudson fixed it.)
