Originally posted by MrFatBooty
That's called bedding in the pads. When you have a fresh surface to work with (i.e. a new or resurfaced rotor) you want to build up a layer of pad material on the rotor to make sure everything works alright. That won't really affect the rotors other than put them through a few heat cycles. It won't hurt, but bedding in your pads isn't some rotor fail-safe.
The best way to keep your rotors from warping is to keep the lug nuts torqued to spec. If you want to get some added durability you can have the rotors cryo-treated.
Actually, the site I was reading was by some guy who says he's been racing for like 30 years. He says that rotors do not actually get "warped" at all but the pulsating you feel when braking hard is from random buildup of pad material on the rotor from not properly bedding them. I'll look for the link, I think it was posted by MojoGS-R on g2ic.com or something.