This is by far the most intelligent webposting on fuel economy that i've come across. It adds a little of the science behind fuel economy. If it does not address your interests in the subject, take the time to read the cited articles at the very end.
Also, try going to youtube.com and searching for hypermile, hypermiler or hypermiling.
There are obviously more ways to save money and they include not driving, using gasbuddy.com and using gasoline credit cards.