New Corolla Auto vs Manual for Better MPG?

I recently bought a new 2005 Toyota Corolla LE with a 5 speed manual transmission. I decided to buy the manual over an automatic transmission with overdrive because I thought it would get better gas mileage. Now I am wondering if I made the right choice.

I have read in other forums differing opinions on this. Some say because a manual transmission runs at higher RPMs at highway speeds (lets say over 70mph) it gets worse MPG then an automatic running at lower RPMs because of the overdrive. Other people say because there is no drive slippage in the manual transmission even though it runs at higher RPMs it will get better MPG.

To be more specific on my car, when I go about 72 mph, I seem to be running at around 3000 rpm. I test drove a Corolla with automatic transmission and it seemed to run 72mph at about 2700 rpm.

I drive around 40,000 miles per year. 97% of which is highway. A difference of just a few mpg does make a difference over the course of this many miles. Just wondering what everyone thinks, did I make the right decision?

well it really depends on the driver, but from all the vehicles i have seen the manual transmissions get better gas milage then the automatics, all the books i have looked at (car buying guides) list the engines, transmissions, and gas mileage (mixed between highway and ctiy) and the manual always is better then the automatic. but this is tested with a driver getting efficentcy not driving normally (racing to work or such)