You're right, a single-purpose mp3 player has a lot of utility for many of the reasons you say. * Easy of navigation when exercising/driving. * Cheap enou

You're right, a single-purpose mp3 player has a lot of utility for many of the reasons you say. * Easy of navigation when exercising/driving. * Cheap enough so you won't cry when it dies. * Cheap enough so you can buy multiple for different purposes. In fact, my favorite MP3 player of all time is a 2nd Generation iPod shuffle. It's lasted for years, it survived going through a washing machine, and it's tiny. OTOH, I'll argue that a good MP3 player isn't a "cheap single-purpose device", it's just a quality single-purpose device that happens to be inexpensive. The price of all MP3 players are so low that the difference between a really "good" one and a really "cheap" one is 20 bucks. You can't say the same thing about still or video cameras. The "cheap" Flip camera has less utility than the camera on my smartphone for one reason only: I always have my smartphone on me. I think stand-alone GPS devices are the next thing that will be obsoleted by smartphones. I don't see TomTom or Garmin being competitive with a smartphone with the same satellite reception and the same maps. If I were Garmin or TomTom I'd start putting all my eggs in the software basket rather than the hardware basket.