[thefultonhow]

Check whether you have a Seagate hard drive -- for a while, they were using Seagates in the MacBooks that went bad left and right. Something about expanding parts inside; I don't remember all the details. I've seen a few MacBooks with that problem, including my roommate's (and unfortunately he was out of warranty, too, so he had to buy a new drive out of pocket). Some have said Apple should recall all MacBooks with that hard drive, but Apple hasn't gone that far yet.

Also, take good care of it, because I've seen a few people who were denied warranty work because there was cosmetic damage to the casing, even if it didn't affect any technical aspect of the computer. I'm getting a little disillusioned with Apple support; they seem to be preoccupied with finding reasons not to cover you, rather than actually providing good service.