With thanks to my friend and fellow military wife Jerri, here is an awesome website with tips on saving gas:

http://www.eere.energy.gov/consumer/tips/driving.html

This website also led me to the following site which helps you find a fuel-efficient vehicle:

http://www.fueleconomy.gov/

Since we're thinking vaguely about buying Jim a new vehicle this year, I found these sites very educational. I hope they help you as well!