Hammer 1.0 was a rock. Hammer 2.0 was a rock attached to a piece of wood, and the caveman that came up with that one must have been pretty pleased; he was the first ergonomicist.
Today we have tons of tools featuring a handle of one material and a head made of another, but there's an ecological problem with this design: The two things can wear out at different rates. In my lifetime I've thrown away scores of toothbrushes because the bristles were spent, but I've never thrown one away because the handle wore out.
Full Circle is a company that "closely monitor[s] the environmental and social impact of our products," and their Laid Back Dish Brush features a removeable brush head so you needn't toss the whole thing out, but can keep buying replaceable heads as you need them. Here's to hoping they start doing toothbrushes.