My son is reaching the LEGO age.  Certainly, he's been playing with blocks since he could manipulate his hands correctly, but DUPLOs don't hold a candle to LEGOs.  LEGOs present two problems: what's the easiest way to store them, and how can you cut cleanup time to a minimum?

Wired's GeekDad found a great solution called the Box 4 Blox.  The idea is simple; once all your pieces are free, just dump them into the top of four stacked boxes.  The biggest pieces will stay at the top, but the smaller pieces will fall through each level, with the smallest finding their way to the bottom once you give the whole stack a good shake. 

I haven't laid hands on the product, but my only complaints are that it's not big enough for some LEGO collections (you should see my nephew's case), and it doesn't have a place to put your "in progress" builds.  I mean, when you're constructing the LEGO Death Star, you need to stop for sleep.