I've been watching the MPG's on the Scangauge (both instant and trip) + Throttle Position. It's changed my driving habbits and does agree with some of the things here. I've found that a moderate acceleration (even a bit of a hard acceleration), with a small letup (allowing it to shift sooner) and then back into it a bit till I get to speed, then backing off to where I can bearly hold that speed or even loose speed slowly, has been the trick for my longer drives (slow accelerations just seem to prolong the lower mpg's). Also, Letting off the gas and coasting sooner and for longer times does make a lot of difference on the scangauge. My real Average MPG killer is the slow bouncy gravel road where I seem to do 6 or 8MPG.
I've been able to get my daily average up to 18mpg if I'm not in a hurry and pay atttention (not pressing the pedal anymore than absolutly necissary to keep going will help me 3 or more mpg and there is really no noticiable speed increase or decrease). When I'm late and hurry to work, I seem to get about 14.5mpg.
All said and done, I consider it a game and a research project, with financial rewards of course (and a bit more relaxed, peace of mind time on my commute)