I Need Some!: Mercury(II) Thiocyanate
Mercury Thiocyanate used to be made into "Pharoah's Serpent" fireworks similar to the "black snake" tablets you light and watch grow into a crusty snake. Unfortunately, it produces mercury vapors during the process so now the tablets are made out of a much safer sodium bicarbonate compound. Boo, I know. Still, wicked awesome if you can get your hands on some. Which, thanks to my ultra-sweet Geekologie connections, I just have. So -- are you thinking what I'm thinking? If you guessed, "glue-stick a bunch to my penis and try to impress women at the bar", you are. High-five! Haha, that was just glue-stick, I swear. Now watch this!
UPDATE: IT BUUUUUUUURNS! *helicoptering* Ladies?
Thanks to John, who once beat Mr. Wizard in a match-holding contest.