here’s the quote from mozillas addon “yslow”
This page has 9 external stylesheets. Try combining them into one.
Decreasing the number of components on a page reduces the number of HTTP requests required to render the page, resulting in faster page loads. Some ways to reduce the number of components include: combine files, combine multiple scripts into one script, combine multiple CSS files into one style sheet, and use CSS Sprites and image maps.
and they should be minified with YUI compressor imho…