Off the top of my head:
- There are 10 kinds of people in the world: Those who know the binary system, and those who don't.
- What do you call two crows on a branch? An attempted murder!
- An electron is driving down the highway when it is pulled over. "Mr. Electron," says the cop, "do you realize you were doing 95 miles per hour?" "Oh no," says the electron, "now I'm lost!"
- Does the name Pavlov ring a bell?