SF zoo pics

When I downloaded pictures from the aquarium, I ran across some really cute ones of Theo at the zoo.  He loves animals and trains more than just about anything.  He hates diaper changes (this week he started chanting, "diaper away" whenever the subject of the diaper comes up) and every morning a ten minute physical altercation ensues with lots of crying and a thrashing/naked/dirty bottom.  It's pretty miserable and someone needs to develop a diaper that doesn't need to be changed, or can be changed once a week (business idea)...kind of like how plants in a fish tank help break down fish poop, can there be a living plant-infused diaper that help break down human poo?