Two weekends ago, Diet Coke was accidentally spilled onto my MacBook Pro Keyboard. The machine, a Core Duo 15" that was among the first of the Intel Macs rolled out, suddenly didn't work the way it used to. Luckily, damage was restricted only to the keyboard: caps lock, shift, b, h, and num lock didn't function. Not being able to type the word "butt" was a pain in the "utt." While I've since repaired the keyboard -- on my own, thanks to iFixit's instructions -- it made me question, again, the value of an extended warranty. Had the damage been worse, I may have had to get a new machine.
While AppleCare is certainly compelling for many (phone support and timely repairs of manufacturer defects by Apple-authorized technicians, among its values), its defect is that hardware repair coverage is restricted to manufacturer defects. And in my case, even if this had been a new machine still under AppleCare, it wouldn't have been covered. So, if you accidentally drop your iPhone in the toilet (it happens) or if, while looking up your Tiramisu recipe in MacGourmet, you happen to spill Kahlua all over your MacBook, you won't be covered by AppleCare.
While researching third party extended warranties, I stumbled upon Square Trade. In addition to covering manufacturers' defects, Square Trade's warranty covers accidental damage. In effect, it's a warranty with an additional safeguard for dings, drops and drenching.
Although the Square Trade warranty covers accidental damage, consider all your options before proceeding with a purchase -- Is it worth its cost? For example, claims for accidentally damaged items (as opposed to manufacturer defects) require a $50 deductible. In the case of the MacBook and MacBook Pro, this narrows the price gap between AppleCare and the SquareTrade price.