While an off-the-shelf chemistry set of today consists of little more than baking soda, some vinegar and a plastic volcano, old sets were filled with good stuff, like explosive nitrates and deadly cyanide compounds.
MAKE has a tutorial, or series of tutorials even, on how to build your own ballsy chemistry set. For instance, pick up Sodium hydroxide that's packaged as crystal drain cleaner. Put the corrosive substance on metal and you get flammable hydrogen gas!
So promise to be good and wear goggles, then hit the link. It could make for a great DIY Christmas gift. [MAKE]