I know the number of each letter in the alphabet - i.e. A=1, B=2, etc. In high school math class, I would get so bored that I would pull out my calculator and start adding up the letters in whatever text we were reading. Weird, I know...
I can tie a knot in a cherry stem with my tongue.
Turn my feet around backwards.
Put my thumbs on the back of my hands.
Roll my tongue.
Put both of my feet behind my head.
So on and so forth.