I was helping a customer carry stuff to his Hummer yesterday and asked him if he had one of those Hybird Hummers that get better gas mileage, he replied "I wish!" he added that he has noticed an increase in his mileage as time goes on now he's getting close to 8mpg vs 7mpg. I didn't have the heart to tell him I see a similiar thing on my Prius as the mileage goes from the low to high 40's.
Just wait until you see the change from low 40s to high 50s. That would have really knocked him over though I'm sure he would have mentioned something about those wimpy little sissy-cars and never getting your money back after the hybrid premium. (To see my anual variances, check my mileage chart in my signature)