I haven't started bike commuting yet, but I plan to soon, because:

1. Love riding the bike
2. Help me lose weight and get in shape (already down 15 lbs this year from running!)
3. Save money on gas.

I drive an Acura Integra GS-R that I've had since 2001. It's been my only car since then, and I love driving it. But it does require premium fuel, and prices are insane compared to the ~$1.50 or less of 93 octane when I bought it in 2001.

I HOPE I'll be able to say that commuting by bike is fun, but I just don't know yet, since the only roads available will be 2-lane roads with no shoulder and most people driving pretty fast. Also there are LOTS of hills. It'll be about 26-27 miles round trip depending on the route. Also due to my wife's morning and evening schedules, I know I'll only be able to commute on Monday, Wednesday, Friday, and even those days I may have to cut my office hours a bit short (arrive a little after 8 on Wed/Fri, may have to leave at 4:30 on Monday). So we'll see how it goes.

At this point I'm not too thrilled with a couple of the roads I have to ride on to get there and back.