Any kind of include, whether it's PHP or SSI, or anything else, does use up processor time on the server. Think about it, the page is being parsed on the fly by the parsing agent. Back in the day, when I first looked into CSS, when it was brand new, doing an SSI include was the general way of doing it. Now that I've finally come back to CSS, (Yes, I HAVE been under a rock of sorts), I thought I'd throw it out there and see what people where thinking on the subject before I spent a lot of time thinking about it. Now that I have thought about it, it is clear that doing a rel link is going to be preferable to an include in most situations I can think of. I must say though, getting up to speed with XHTML and CSS took a lot less time than I thought it would. It only took me two days to go from a clunky site with lots of tables and spacer gifs to an XHTML 1.0 Strict compliant site. I don't have all of the CSS implemented as clean as I'd like yet, but it is 100% compliant. It also looks much better.😃
Nick