Ok.... I like this one:

The object is to increase your chance of living greater than 50:50.

You are a mute prisoner sentenced to death. Your only chance at freedom comes from the blind-folded executioner picking from 50 white and 50 black balls. You apparently were captured by a pretty humored individual. But we all know you are smarter than they are =)

The night before you are given a box of 50 white and a box of 50 black. You can mix them up however you like. But if the executioner picks a black ball you will die and if he picks a white one you will live. How do you give youself a better chance of survival?

So long as you do not remove any balls, alter the balls in any way (coloring them or squishing them etc...) the executioner will hold up his end of the deal and make it a completly random drawing with no peeking.

Have fun!