Time for a funny:

'A Mathematician, a Biologist, and a Physicist are sitting in a street café while watching people going in and coming out of the house on the other side of the street. First they see two people going into the house. Time passes. After a while they notice three people leaving the house.

The Physicist concludes: "The measurement wasn't accurate."
The Biologist concludes: "They must have reproduced."
The Mathematician concludes: "Now if exactly one more person enters the house, then it will be empty again."'

lol...

That's another good one.

I don't know that I've shared this with you:

http://xkcd.com/435/

'A Mathematician, a Biologist, and a Physicist are sitting in a street café while watching people going in and coming out of the house on the other side of the street. First they see two people going into the house. Time passes. After a while they notice three people leaving the house.

The Physicist concludes: "The measurement wasn't accurate."
The Biologist concludes: "They must have reproduced."
The Mathematician concludes: "Now if exactly one more person enters the house, then it will be empty again."'