What do UFO's and smart blondes have in common?

You keep hearing about them, but never see any.

What is the difference between blondes and traffic signs?

Some traffic signs say stop.

Why are all dumb blonde jokes one-liners?

So men can remember them.

What did the blondes right leg say to the left leg?

Nothing, they haven't met!

What's the difference between a blonde and your job?

Your job still sucks after 6 months.