Somewhat the kitchen mad scientist, I have created a living organism in a jar using only water and flour...
My wife refers to it as my girlfriend.
Utilizing very ancient techniques, I combined organic flour and water in specific proportions, captured wild yeast inside of the mix, and created a life: my wild yeast sourdough starter. I use parts of it to make bread.
I have to feed and water it regularly, or it will die. Sometimes you can see it breathing.
If anyone's interested, I have a baking site, as well. I'm planning on putting up a how-to about my starter in a few days.
http://www.improveyourbaking.com/