I was also going to suggest throwing it into a fire... aparently I'm not original. but still, explosions are fun.
one time when I was celebrating new year's eve with some friends(and a lot of weed and meat), one of them brought a bag full of empty paint cans(he is in the graffittiscene), and even those empty cans had some nice bangs in them. the fire was in a brazier, and afterwartds some of the metal bars had been partly detached and bent.
I would imagine a not-empty can of gas giving a nice spectacle. I wouldn't stand cose to it though.