when loading gas into a billy can in the back of the truck - you're not earthed. tech question, how well is you're gas tank earthed?
cell phones - is see no spark there, unless radio waves can ignite. hmm
a running engine - isnt the internal combustion engine a controlled explosion, aren't all those sparks supposed to live inside a combustion chamber.
static - very dangerous thing when filling up. I try not to rub my fleece then touch the end of the gas nozzle.
smoking - if someone is smoking at a gas station what do you do? confront them on their stupidity, stare at them dissapprovingly, ignore them or pee in front of their vehicle and say you're a fire fighter.
I must admit though, having lived here in the USA for 6 yrs, lots of people do underestimate the dangers of refueling. Back in England they appear to be lot more aware / scared. Hoorah for public service announcements.