Dynamic CSS Generation

Not exactly what you asked but I thought I'd mention, I use this for
dynamic css and love it.

http://www.misuse.org/science/2006/09/26/dynamic-css-in-ruby-on-rails?story=20060926084103529

Basically you create a controller (rcss_controller) and your css
file(s) are just templates which can now contain ruby code, instance
variables, etc.

linoj

Another good reason to use conditional comments is that you aren't
preventing yourself from ever being able to use page caching... Then
the html output is the same regardless of the UA. Of course this
doesn't matter if your pages are all user-specific anyway, but some of
the cms stuff I've built does very well with page caching since
everyone sees the same page.

Matt