I've seen a lot of cigarettes dropped into gasoline during the Dark Ages (when I pumped gasoline for $.25 a gallon!)

Mythbusters did a show on gasoline explosions, primarily about using a cell phone while pumping gas.

They couldn't make the gas in the tank explode even when they caused a static spark right at the filler mouth.

They also tried to see if a lit cigarette would ignite a pool of gas. They only proved what I've known for years: it nearly always takes an actual flame to get a gas puddle to ignite. A glowing ember just won't do it.

This may be because of the theory above...perhaps the gas right at the surface of the pool was too rich to ignite?

And in addition to numb-nuts working on a 'empty' gas tank (it should be filled with water, or an inert gas like nitrogen ) and blowing themselves through a wall.

I strongly advise against using gasoline as a fire starter.

If you just put a little on your wood and light it off, you're probably OK - but if you squeeze the can to 'shoot' more gas into the fire, that flame can run up the stream of gas, and enter the can when you release your hand pressure, allowing the can to 'inhale.' A guy two campsites away blew all the windows out of my motorhome by playing with gas. I wonder if his hair ever grew back?

Steve