Apple computers and gadgets are pretty well-known for their determination to present a minimalist interface. The mouse has one button, the iPod has a click wheel, MacOS has always strived to require as few clicks as possible for the majority of user tasks. Aesthetics take top-seat when it comes to device design. Look at the iMac, the PowerBook/MacBook, iPod and now the iPhone. Almost no seams, and more importantly, almost no buttons.
Turns out that Steve Jobs has a thing for buttons. He hates them.
The iPhone represents Jobs's biggest victory over the button, as it only has one, using a touch interface instead of a more traditional keypad or stylus interface. Simplicity and appearance, the drive to be as unintimidating as possible to the average user. Those are the driving goals of Apple gadget design.
If you want to read more of the great battle against the button, check out the Wall Street Journal article below.