iFixit posted an especially detailed blog on the matter titled "Apple's Diabolical attempt to Screw Your iPhone." It states that there are 3 variations of the five-point pentalobe circulating in Apple hardware. Those of you outside of the U.S. are unhappy to understand that "non-U.S. iPhone 4 units have had smaller versions of those evil screws all along."
But what very gets Wiens going is this: iFixit claims to possess spoken with many Apple store Genius Bar workers who make sure that when shoppers are bringing their iPhone 4 in for repairs, the corporate is switching screws while not consent, in spite of the service performed.
Of course, iFixit contains a monetary stake in calling attention to matters. It's readied a $9.95 resolution amusingly known as the "iPhone four Liberation Kit," which has a driver to rid your phone of the proprietary pentalobes and replace them with customary Phillips screws.