Confusing gas purchase practices.

Hi all, over the labor day weekend I noticed many strange gas purchase habits by friends. For one thing, I noticed a few would drive a mile or two to the next station if the price was $0.02 cents lower. That makes no sense to me. And the station that was $0.02 lower had an extra long line because it was known by the locals for being the cheapest in a 5 mile radius. This is an expensive $0.02 per gallon to save in my book. First you have to burn about two miles of city driving gas to get there. Then you idle in line waiting for your turn to pump while the AC is keeping you comfortable in the hot summer sun. I would think these differences would eat up anything you can save. My personal habits are just to fill up when I need to, but just make sure the price is reasonable. That's my $0.02 forsaving on gasoline. What's yours?