"A smartphone is a mobile phone offering advanced capabilities, often with PC-like functionality" according to wikipedia. The Apple iPhone isn't a regular smartphone. In my mind the iPhone is more than just a phone that can call, send text messages, view photos, and with the Windows Mobile Phones work with Word mobile.
Apple makes everything the way they want and of course different. As there are no complete set of rules to what a smartphone can have, Apple went all out with the iPhone 3G and now the iPhone 3Gs. The first iPhone was the Simon that featured a calendar,address book, world clock, calculator, note pad, e-mail, send and receive fax, and games. It like the iPhone was touch screen with no physical buttons as well, but the touch screen on the iPhone is like no other. The screen on the iPhone is multi-touch for those who didn't know and what that is it allows many different finger techniques to be used for many features on the phone.
When most people think smart phone they think BlackBerry, BlackJack, Palm or a Nokia phone. When I think smart phone I think iPhone. The iPhone can do all of the things I had said earlier, but it can also... play third party games via the app store, have billions of free and paid applications via the app store, be a mobile device that isn't just a portable computer, but way more complex and better.
Why would thousands of people wait in line for hours waiting for the latest and greatest iPhone? Because it isn't just a regular phone it is once again much more.