Some devices have geolocation, which could allow users to select from a geographically sorted list of time zones. A graphical selection interface can allow users to select from a map based on the timezone city coordinates in zone.tab. And packagers are of course always welcome to provide more sophisticated selection mechanisms on top of the minimimal facilities offered by tz. The user experience of enabling effective time zone selection by end users is already well outside the scope of the tz project.
-cott