If you have read anything about hypermiling, you know there are techniques to help improve your gas mileage. I have been driving at or below the speed limit consistently, accelerating slowly, decelerating slowly, using cruise control whenever possible, and generally just not driving fast.
This accomplishes two things.
a) Most importantly: Reduced Stress. I have enough things stressing me out on a daily basis. I do tech support. Holy Stress Batman! Driving slower is one of the biggest factors to help me reduce stress.
b) Saving Money on Gas. Who doesn't need that?
I filled my tank today, and was astonished when I noticed I'd driven 312.7 miles on 9.88 gallons of gas. I usually cannot pull more than 300 miles from a full tank, let alone 10 gallons.
That's 31.6mpg! My car has over 130k miles on it. Very impressive!
Biking to work helps, because I'm not using the car for short distances, so it's all highway miles.