Fuel cost calculator

Via the blog Lifehacker, here's a cool tool for determining whether that extra trip this summer is really worth it. The online trip cost calculator gives you a map to your destination, a la Mapquest, but then also factors in average fuel costs for the area you'll be driving through, along with your vehicle's fuel economy (and a government link to determine that if you don't already know it).
Depressing, maybe, but certainly poignant, and valuable information these days.