Jeremy Keith reports from FOWD that, during his presentation on From Design To Deployment, Jon Hicks recommended using @import to load separate stylesheets:

For CSS, Jon begins with a basic file that tidies up fonts and spacing but doesn’t do any layout. Now he @imports a reset stylesheet and a typography stylesheet and a layout stylesheet.

According to the recently released 20 additional high performance rules, it is actually preferable to use elements rather than @import. The reason given is that when a browser encounters an @import directive, it has the same effect as a