A PlayStation forum poster claims that a Sony customer service rep told him his broken PS3's warranty was voided because he plugged the console into a surge protector and not a wall socket, and that he'd have to pay $150 to fix it. When reached for comment, Sony said this wasn't the case and that your warranty won't be voided if you use a power strip.
Even if the forum poster was told that his warranty was voided, it could have been a result of a customer service rep not wanting to deal with this guy rather than some kind of company policy.
We've also heard that Microsoft's recommended usage is to plug your Xbox 360 into the wall, and not a power strip, because a poorly made surge protector or an overloaded strip can cause damage to your console from not supplying enough power. We're still waiting on official word from Microsoft to see if it's against their warranty to plug a 360 in this way (it's probably not). [Wired]