This made our morning news this morning, remember this being brought up some time back on this forum. Thought I'd pass it along. This is from http://kfvs12.com/ .

"Groups Warn of Potential Static Hazards at Gas Pumps"

The colder it gets outside, the more tempting it is to sit inside your vehicle while you're at the gas pump.
But before you do, the Missouri Petroleum Marketers and Convenience Store Association and the Missouri Department of Agriculture want to remind you about the danger of static electricity fires. Since 1999, the Petroleum Equipment Institute has recorded around 125 cases of static-sparked gas fires.
A fire that happened at a Cape Girardeau gas station earlier this year may account for one of them. Firefighters never really knew for sure what caused a mini-van to explode at the Huck’s Convenience Store on April 7th, but static electricity seemed the most likely cause. Lisa Scherer, of Oran, had reached back inside her mini-van after she began to pump gas. Then she grabbed the fuel nozzle again. “When I did, it was just flames shooting out. I mean, they were just shooting out,” Scherer told Heartland News later that day. “I don't even know where it was coming from! It was just a big ball of fire!”
Luckily, no one was in Scherer's mini-van or the car next to it when they were engulfed in flames. But other victims of static fires across the country haven't always been so lucky. Cape Girardeau Fire Battalion Chief Fred Vincel thinks drivers should be aware of what causes static fires, and how to prevent them. “That sliding motion you make when you're getting in or out of the vehicle is what generates that static electric charge,” he explains. “And the charge is going to go someplace as soon as it finds a source where it can go. We don't want it to be the fuel nozzle.”
Vincel says the best way to keep that from happening is by not getting back inside your car until you’ve finished pumping gas. If you absolutely have to get back in the car, maybe to grab your wallet or check on the kids, you want to make sure to touch something that's metal before you grab the fuel nozzle again. Vincel suggests touching the car door or a nearby metal pole. By doing that, you discharge the built-up static electricity. “If you don't discharge it prior to getting to the pump and you touch the nozzle, then possibly that static electric charge could ignite the vapors that are coming from the tank,” says Vincel.
Vincel also warns against doing other things that could ignite vapors while you’re pumping gas. Don't smoke. Don't leave your engine running. And if you have a cell phone or any kind of electrical device on your person, either leave it in the car, or turn it off while you’re at the pump. It's advice that's repeated in signs at most gas stations, and Vincel says they're there for a reason
The National Weather Service warns that the risk is even greater during cold weather when you have the heater running in the car, because that reduces the humidity in the air and increases the chance for static electricity.
Here is another link posted on the site for further reading:
http://www.mpca.org/