Seraphin's story is a great read, so I just suggest you head over to his blog and check it out. But why does he appreciate the phone so much? Apple's VoiceOver feature is a big plus -- it allows people without sight to browse and control the iPhone's touch screen using audio feedback, reading off messages and even checking things like stocks and weather all by translating it through the speaker.
Seraphin even describes using a color picking app to use the iPhone's camera to "see" colors around him, with VoiceOver reading off descriptive names of the colors coming through the lens. That's pretty incredible, and something only the iPhone, with its extremely mobile combination of technology and UI design, can easily make possible.
Seraphin still has an issue using iTunes, and not all apps are, of course, quite as accessible as Apple's guidelines ask them to be. But it's awesome to hear how Apple's approach to technology, combined with all of the various apps out there, can make a significant change in this man's life. In fact, last week he got himself an iMac.