I'm using Debian Lenny. I'm trying to switch over to from apache to nginx--and so far I like the transition. But everything I'm reading suggests to use php-fpm, but since Lenny comes with 5.2.6, FPM is a patch, and I'd have to uninstall the PHP debs and install php from source--at that point i could just as well install the latest version of PHP from source.
Currently I'm somewhat following this guide but it seems pretty inefficient, running nginx directly against php-cgi... its spawned processes seem to spike up to 10% CPU per each page load.