If you take the powder off the sparklers, put it in a tin and leave a small hole in the lid, when you light it sparks spray up into the air. It might take a few tries though. Leaves black metallic stuff lying around.<br><br><br><br>
The same can be done by taking the lead from a shotgun shell and placing a sparkler in it. When it gets to the detonator it gets more interesting.<br><br><br><br>
A .22 bullet with the lead removed can have the end flattened so it's almost closed, then let a bit of powder fall out and light it (so the flame can get to the shell of course) and it will sort of launch backwards.<br><br><br><br>
The flint from a lighter, when heated until glowing red and thrown to a hard surface like concrete, will explode like a miniature firework.