In general, I think extended warranties are not worth the money. However, in the case of a laptop I think extended AppleCare is a wise idea. In most computers, there are few moving parts. In a laptop however, in addition to the hard drive, there is a battery and the mechanisms that lock the hard drive for transport. Also remember, using the laptop on your lap puts more stress on your hard drive. It has to cope with your movement, however small, while its pirched on your lap.
In another situation, a school I do some volunteer Systems Administration work with purchased 10 iMacs with extended warranties. We've had several occations to take machines into the shop for some maintainance including one hard drive failure. Having what is in reality a 4 year warrnaty on the hardware is GREAT!
I'm also considering the 3 year Software Maintainance program which would cover OS updates and other software updates.