A while back I read about a concept now known as "hypermiling," which in short is deliberate alteration of one's vehicle and driving habits with the aim of maximizing fuel economy.
This past weekend I was on the road for a bit, and on my return trip I decided to put as many hypermiling techniques into practice as I could (the ones that don't require alterations to the vehicle itself, that is). I drive a 2001 Hyundai Accent, 5 speed manual, with no AC system.
Result: I achieved roughly 51 miles per gallon!
Interested? You should be. Hypermiling works with any vehicle out there. Click here for some further reading on the subject.