Friends, Stay-at-home Dads, Mommies it is a fundamental rule of the universe. A toy left out is uninteresting. But a toy that is put up is interesting, and should be pulled out. This is doubly so for a toy that a father just put up.
They, that is the little rugrat in your life, wants a clean house...so he can mess it up.
My recommendation? Take your digital camera with you when you clean up. Take a quick snapshot as soon as you are done so you can show your Other Half that you actually did do work today.