Preventing frozen pipes, heat or drip?

[Paul Sandhu]

Thought this would be an appropriate question considering half this country is going to be under a deep freeze.

Do you leave the central heat on low or do you let some faucets drip water to prevent frozen plumbing? 

I usually do both, set the heat as low as it'll go and drip cold water in one sink and hot water in another.  Also, I put some automotive antifreeze in my washing machines that are in an unheated storage building and run the spin cycle for a few seconds.