My current commute starts off with a 25 minute/ 5.25 mile ride to the train station, waiting around for the train, 20 minutes on the train, and then a 25 minute /4.5 mile ride to work.

The only bad part of this is that the Chicago Metra train only runs about once an hour, so I always deliberately have to leave early so that I don't risk missing the train.

(The Chicago El train is much more bicycle friendly. If you miss a train, the next one should be by in just a few minutes. The Chicago mayor, Richard Daley, has talked about extending the El out to the western suburb of Schaumburg, where there are a lot of businesses. Although his motivation for doing so is to increase access to O'Hare Airport from the western 'burbs, it would be a very good thing for those of us who prefer not to use cars.)