The iPhone is: known to focus on usability; made by Apple; has iTunes, a big screen, a great screen, a wide screen; has a PDA brother -- the iTouch; runs a version of a real operating system; and is made by the manufacturer of the most popular portable digital music players of each of the last 7 years or so. Finally, Apple is not a phone manufacturer but a designer of usable things -- people want to buy something that is made by Apple, and not a phone company. The resulting popularity, promise of an SDK, a commitment to the product line, and an exciting bridge of software and hardware gets developers on board. This gets the iPhone to the point where all of a sudden, it doesn't matter who created it--Microsoft, McDonalds, or Staples--or exactly what it's capable of: everyone else is using it, which means it's now a "standard", and a good enough reason to make that your next phone.