Perhaps the most groundbreaking change in Android 4.2 is support for multiple users on tablets. The latest Android OS allows you to set up numerous accounts on your device and switch from one to another with a couple of quick taps.
The feature makes it easy to share a device with family or friends: Each user has her own home screen, apps, wallpaper and general settings. What's more, every user's data -- photos, files and so forth -- remains inaccessible to other users.
(Some basic system settings, such as Wi-Fi configuration, are universal and shared among all users).