...and your pant legs, socks, and shoes. For years I've been an all-weather commuter with full fenders. I recently got a new rig that currently has Raceblade clip-on fenders. The rear fender ends behind the seat stay, and my seat tube, FD, and lower parts of my legs get sprayed now.
and your headset clean. The Raceblade front sits entirely behind the fork crown, so I use a Lizard Skins Headseal to keep junk out of the lower headset race, having had many years success with similar products on my mountain bike.