I got my hands on the first iPhone on June 29, 2007, and it was immediately obvious that it would forever change the mobile phone industry. I picked up my phone at exactly 6:00 p.m. that night -- the moment it went on sale -- and when I wrote my first impression article at 11:00 p.m. that night, I concluded, that the "iPhone's software represents a truly remarkable accomplishment. Sure, the device's ultra thin case and large 3.5 inch display are nice touches, but what really stands out is the user interface that can best be described as inspired. Regardless of how well this device ultimately does, it will always be remembered as the phone that broke the mold from which all others were fabricated."
In some ways my early review was an understatement. As you look around at the market today, it's obvious that Steve Jobs' inspiration was contagious and quickly emulated by all of his major competitors. Google, whose CEO was on the Apple board at the time the iPhone was released, wound up acquiring Android and spearheaded its own line of very popular touch screen phones with a pretty similar interface. Sure, there are differences but the fundamental interface design -- using your finger to launch and work with apps -- is extremely close.
Besides Apple, Android is the other big success story but there were plenty of other attempts to compete with iPhone from Palm (which was later acquired and then killed by HP), Research in Motion (which struggles for survival after several failed attempts to emulate Apple) and Microsoft which is probably the most innovative of the non-Apple smart phone developers with its own touch-screen interface that's noticeably different from iOS).
The iPhone also helped create the modern tablet. Although Steve Jobs later said that Apple conceived of a tablet before it built the iPhone, the iPhone's interface, basic design and operating system served as the basis for the iPad and the two devices still share a common operating system and run many of the same apps. It's not fair to call the iPad a "big iPhone," because its form factor opens up unique use cases, but essentially that's what it is. The same is true with the many Android tablets including Google's outstanding new Nexus 7 that shares an operating system and app ecosystem with Android phones.
As with any birthday, it's appropriate not just to recognize the guest of honor but also the parents that brought that guest into the world so this is a great time to thank the iPhone's father, the late Steve Jobs, who had the genius to support those around him with vivid imaginations and the courage to Think Different.