Software inventory management

[stan]

Sudenly there is an improved desire to keep up to date on the latest
security fixes at work. I've got about 50 machines that I manage. OpenBSD, 
FreeBSD, Linux, Solairs, and HP-UX.

I am looking for recomendations for a (hopefully automed), prefereably
web based tool to keep up with what versions of OS, OS patches, and ports
are installed on these machines.

Could anyone with experience using such a tool share their experience, 
both good and bad for such [ackages?

-- 
Unix is very simple, but it takes a genius to understand the simplicity.
(Dennis Ritchie)