The Alchemist (The Discovery of Phosphorus Through Henning Fire in Hamburg 1669)
Here is a weekend project for Sami, TreeHugger's champion peecycler: make phosphorus from your own urine! It's toxic and explosive in its pure form, but chemistry is fun, right? IO9 describes the process:
First, you should allow some urine (preferably your own but I don't judge) to sit in an open container for about a week. Keep it in a room away from people. During this week, get some charcoal and grind it up into very very fine powder. You should make about two tablespoons of powder. Also get two tablespoons of powdered cinnamon. Mix the powders together.
You then mix the urine with the tasty powder and heat it in a retort like that kid in the chemistry set has. IO9 suggests that you wear protective clothing and eye protection, and don't breathe, because "Urine contains urea, and that breaks down into ammonia. You want to be careful with your exposure." Oh, and keep it under water or it will spontaneously ignite.
Then again, Sami, maybe this isn't such a good idea. More in IO9
More on phosphorus:
Fred Pearce On Peak Phosphorus: It's Time For Pee-Cycling
Are We Near Peak Phosphorus?
P is for Phosphorus (As Well As Human Urine)