On my first commute, I remember thinking if it was such a good idea, because I was hurting at the end (and it's just 11 miles). Now, I love it, and dread driving the car. (been commuting about a month now)

I second the WTB saddle. I love mine, and I never have any soreness.Yes, I said NEVER. It's not even an issue anymore.

I also carry spare tubes and a patch kit, in case of the dreaded double-whammy (spare tube goes flat, too).