i havent checked out those sites lately, but when using them before, i suppose if you care about saving 3 or 4 cents a gallon they can be useful, but it's really not worth going thru any trouble to save $0.50 on a fillup. makes me think of my wife who is constantly telling me to fill up when we have 3/4 of a tank and drive by a station where gas is a couple cents cheaper than the station by our house. forget it, not worth the time to save a dime (of course as i sit here typing this, she's on her computer spending hundreds of dollars buying baby pictures she had taken at a studio. sigh.......)
