"This screw head is new to us. In fact, there isn't a single reputable supplier that sells exactly the same screwdrivers Apple's technicians use -- which is Apple's point. They picked an obscure head that no one would have," iFixit said. "Apple chose this fastener specifically because it was new, guaranteeing repair tools would be both rare and expensive."
Apple reportedly began using Pentalobe screws to secure the mid-2009 MacBook Pro's battery and they're used on the lower case of the latest MacBook Air models to prevent users from accessing the system's internals. Additionally, many non-US iPhone 4s shipped Pentalobe screws from day one and new US versions use the obscure fasteners.
iFixit also notes that if you bring your iPhone to Apple for "any kind of service," they'll swap your Phillips screws with the new proprietary type. As much as we hate intentional roadblocks, the average user isn't going to dissect their smartphone. For you DIYers, iFixit is selling a new "iPhone 4 Liberation Kit" with everything you'll need to get inside.