Are you getting as much out of your commute as you could? My congratulations if you find it valuable and rewarding time. I suspect, though, that many people feel it is quite the opposite.
I am really happy with mine since I traded in driving for walking and transit. I get a refreshing three-block walk down my hill, a short ride on the Muni metro, a two-block walk over to the transbay bus terminal and usually a good 15-20 minutes of comfortable riding over the Bay Bridge to the stop three blocks from work. By the time I reach the office I've moved around a bit enough to wake up properly and often seen some pretty views from my high seat on the bridge.
What makes it really valuable to me is that I can download my mail before I leave the house and sort through it all before I get to the office. I often am able to compose answers for all the quick questions and usually have time left over to plan out the rest of my day. When I arrive at the office and plug in, I send mail and move on to the appropriate next action, rather than just reacting to whatever is coming at me.
On the way home, I usually just relax and look out the windows at the view. Sometimes I read and sometimes I watch a bit of a DVD on my laptop (old tv shows I'm catching up with are particularly suited to this).
I know folks who drive who listen to books on tape to make their commutes more relaxing and let them claim some of that reading time they wish they had more of. There are other tricks for the car as well, such as practicing a new language or keeping up with your daily news intake with podcasts or NPR.
Start looking at your routine and see how you might make it serve you better.