I've been telecommuting the past few years so I don't get to bike to work. :( BUT I can bug out during the day and do laps around my neighborhood on my roadie, so that helps. :)
The one time I was regularly biking to work was a several-month stretch in Portland, after moving there with a net startup which croaked some months later. :(
I was fortunate in that way - the ride was only about 25 blocks, a good portion of which a) had a bike lane, and b) was slightly downhill going in. So the ride to work was not strenuous, hence I didn't even have a chance to get sweaty at all. And the ride home was uphill, and I would often push it riding home, to get that little workout.