(YAHOO! FINANCE) — We've all been there. As we head to the register to buy a new laptop or cell phone, we face the aggressive sales pitch to buy an extended warranty. And many of us do spring for this additional service contract. In 2010, we bought 250 million extended warranties, according to the Service Contract Industry Council. But are they really worth it? It's a hot debate and the answer is: It depends. Though, in most cases, you're better off just saving that money.