I guess if you got the money its OK, but I figure the reason they sell Extended Warranties is because they make money on them. If you don't use it, it's your money that they are making --taking.
Also read the fine print. .. Somewhat unrelated but still pertinent. I recently took out a Service Contract with Staples for a printer. I am a photographer and use my printer hard. When the printer broke, Staples replaced it with a rebuilt printer and said that satisfied their obligation. The rebuilt failed right after the 60 day guarantee ended, and even though I had paid for a 2 year contract which had about 6 months left, I was SOOL (EDIT)Out Of LucK