I watched both of my non-techie parents use my iPhone two years ago when I brought my family home for Xmas and by new years day they both had shiny new iPhones. They hardly ever used the computers I set up for them and would routinely update/replace whenever I returned over two decades but they dived right into the iPhone. My mom had a 3GS before I did.<p>The learning curve was not as steep and the rewards for learning the device were more direct and obvious.  Anyone can eventually learn to use a computer running Linux, OS X, or Windows if they really have to, but there is a big difference between needing to learn how to use something and getting past that initial hump so quickly that you don't even notice it.