Do any of you use the GasBuddy app? It is an awesome, free app for finding gas and diesel at low prices near you, or along your path (well, you can look at a map...it needs to be mashed up with google maps). For instance, when I went to Mississippi recently, I found a sole fuel station on a lonely exit in Alabama that had diesel at $3.00/g, which was relatively cheap compared to $3.19/g near my house and $3.09/g in Dallas, GA.