This is kind of a bold step not quite backwards, but sideways in the development of portable music players: The Playbutton, a pin-on button containing a single predetermined album. You can pause, skip tracks and adjust the volume, that's it--no adding your own tracks or futzing with the playlist order.
The Playbutton is obviously not meant to be an MP3 player replacement, but perhaps a promotional item for a band, given that one side of the device is a printable blank circle. The lack of track choice harkens back to the days of vinyl, and this will probably appeal to music purists. I personally can think of only two albums I enjoy hearing in their entirety (Radiohead's OK Computer and the Black Crowes' Southern Harmony and Musical Companion, judge me if you will); what do you think of the Playbutton's "Desert Island" aspect?