Toyota service will come to your house and 'whack' you upside the head........
Seriously, I didn't change mine until 50k, with no noticeable problems. But, there are those who will say that if you don't follow the service recommendations, you might jeopardize your warranty. Not sure how true that is.
On a more serious note, the stock plugs are cheap and easy. Don't pay a stealer to do it. Get the tools out and get cozy with your truck. These are the easiest plugs I've ever changed. Not sure if keeping them in too long will freeze them in the heads but why risk it.
i can't seem to find a thread that has pictures of changing out the plugs. does anyone have the step-by-step breakdown with the pictures? and what tools do i need? how much money do you save by doing it yourself?