Since having children, what products have you thought "someone really should invent a xxxxx it would make life a lot easier/better/more fun"?
Why doesn't someone do reward charts and stickers that actually look nice - designer reward charts. I would buy them. I really hate potty training enough as it is without having to look at some overpriced tatty piece of clip art hell at regular intervals throughout the day.
Obviously only if it is not a top secret product which you are about to patent...