Okay, that's funny.
On a more serious note, the best actual idea I ever heard was Andrew Tobias' "compound interest" game for your kids...
I've probably got the game garbled, but as I remember it, you tell your child or children that you'll give him, her or them five bucks to start but then pay a 10% interest rate every day for as long as 30 days.
If a kid goes the distance, it ends up being around $80 by the end of the month.
But you let a kid take the money early... and in fact, if one kid takes money after a week (about $10) and the other kid after the month ends (nearly $80), everybody really learns the power of compound interest.