20 miles, one way, is way too far. If I had to do it and I was dead set against buying a car, I would get an electric bike. It has all the advantages of a bicycle, no license, no registration, no insurance, no gas, no pollution, cheap tires that you can change yourself, and on and on. Someone in the commuting thread, JoeyBike?, test rode a Specialized Turbo and said it was spectacular. He said it would go 28mph. You would get to work in less than an hour and re-charge at work. Best of all, you wouldn't be a tired wreck when you get home.