Advertising on Cows! Why not kids?

Why stop at cows? Why don't we brand our school children so they display our messages on their way to school? That way we could influence an emerging market before they even acquire their right to choose! Or lets brand the trees in our gardens, they're our trees, aren't they? Or what about our pets? Cats get around quite a lot - let's paint the Nike swoosh onto their backs! Which would also make them easy to recognise when they get lost! You just phone up Nike and tell them that one of their billboards is drinking milk in your kitchen! What fun!
What do you think? Any further great ideas?