It varies. At worst it's about 8 hours one way, and at best it's about 30 seconds.
The thing is, I usually work from home, so my "commute" is walking from my bed to my couch, with a brief detour to turn in the coffee maker. But, since I work as a consultant, about every other month I have to fly somewhere for 3 or 4 days to do some on site stuff, hence the 8 hours one way.