If you'll pardon the devil's advocate bit...

Caching isn't really the issue - you can use mod_cache, or make your own
using CSS::Minifier. I think Bjorn was questioning the
Apache2::Filter::Minifier:: approach.

Here's a different take on Apache2::Filter::Minifier. I run a small web
dev shop, I code perl and manage the servers, and I have a small team of
web developers who make works of art using JS and CSS. I have a few
hundred man-hours* per month for development. We're talking about
simply deploying a module to speed up some sites, without it using up
many man-hours. Thanks, Community!** This helps me proudly tell my
customers about mod_perl, and in will help my business get to the point
where we can contribute code and ideas back to the community.

* woman-hours too, of course, but it's still all blokes here
** Community as in Graham, Geoffrey and co