Check out this experimental toothbrush; it works like one of those punching clown thingys that never fall over.

From the creator’s web site:
DEWS does away with concerns about whether your toothbrush is resting on an unhygienic surface. This upstanding toothbrush makes use of a weight at the end of its rounded handle to create a centre of gravity at the handle base. When the toothbrush is set down, it will sway momentarily until it reaches a position of balance – much like a tumble doll.
I love the idea of never needing to keep my toothbrush in a cup, but, if you really wanted it to be hygienic, you’d need a little cover for it too.
Or is that me being a bit to anal retentive about it?
That said, my toothbrush sits in a mug that gets washed every few weeks to prevent too much mould build up.