I remember once when I was a kid... I found a lighter somewhere and I don't know why but I started to play with it around my old house's propane tank and I almost started a fire beneath it =/ At that time, I was like 8 and unaware of the danger of it
Fortunately, my mom was there to prevent anything from happening.
But on another side, make burn some iron oxyde and you got yourself what we call "Thermites" that can make any metal melt
Perfect for stealing banks
And another thing I like to do is take two lighters, light up one and let out the butane out of the other one and light one lighter with the other. I think it's really cool. And sometimes, I like to light a lighter and fix the flame; I can fix it for a whole 10 minutes without giving attention to anything that revolves around me O.o