In terms of usability, Apple products like the iPhone and iPod are design icons. Elegance, utility and simplicity rolled into beautiful compact devices.
Many years earlier, in 1984, Apple did something similar to the computing world, and brought the GUI and mouse to life (thanks to Xerox). Since those paleolithic days, it has always stuck with a "single-button" mouse, the defense being more buttons are "confusing to novice users", or some crap like that.
That unrelenting stubbornness continues to this day.
In 2006, I bought a MacBook Pro at work, with a single button mouse as shown above. For the most part, I like my Mac, although I prefer a similarly priced Linux machine running Ubuntu.
I never really liked the one button mouse, but out of the compromise that is this life, I forged a working relationship with it.
In other parts of the world, the number of buttons on "mice" have increased, as shown by the five button mouse here (from wikipedia).
Last month, my wife got a new Mac from her workplace, after her old Mac gave her repeated battery problems.
To my surprise and utter disgust, in these spanking new machines, they got rid of the only button left!
And replaced that with a trackpad, instead. So her computer looks like the picture below.
No buttons. See!
The whole trackpad is the button. WTF?
To add to the insult, it now has all the cool features such as zooming using two fingers, borrowed from their iPhone. Personally, I find it extremely annoying, since every time I try to select some text using two fingers (and there is no button to anchor one of the fingers, remember), it thinks I want to zoom.
To think that they wanted to stick with a single button because novice users would be confused.
Heck, I've been using computers for 20+ years, and I am confused with this crap!