When you subsequently launch iTunes in any account, this is the library that will appear. Whenever anyone with access to this library adds media, it will appear for all the accounts that use this library. Note that you must quit iTunes before moving to another account. iTunes will pop-up an error telling you that you can’t access the current library if iTunes is open in another account.
With this setup comes a measure of responsibility. Everyone using this library has the ability to add and delete music. Therefore family members should agree on the rules—no tossing out media and no making inappropriate media available to those who shouldn’t be exposed to it. It’s also a good idea for each family member to create a folder that contains their playlists. To do that, just choose File -> New Playlist Folder, give it an appropriate name, and populate it with your favorite media. That way each family member has access to just the media they want to enjoy, plus it makes syncing iPods and iOS devices easier.
iPhoto libraries iPhoto works in a similar way. To share a single iPhoto library with everyone using the Mac, locate the existing iPhoto library that you’d like to share (it will be in one user’s Pictures folder) and move it to /Users/Shared. Now launch iPhoto with the Option key held down. In the resulting iPhoto window, click the Other Library button and navigate to the iPhoto library that you just moved and click Open. Quit iPhoto and repeat this process for each account. When using Lion you may see a warning that the library is locked and you need to authorize it in order to alter its permissions. Do so and the library will appear within other accounts.
From this point forward, iPhoto will use this image library for every account you’ve configured. Any images added to iPhoto will be available to every account linked to this library. The same warnings apply: Each user must quit iPhoto before another user can access the iPhoto library you’ve shared. Also, any images deleted and permanently thrown away when someone empties iPhoto’s trash are gone for everyone.
Time Machine backups As an administrator, there’s no special magic you have to perform to back up all the user accounts using Time Machine. By default, Time Machine backs up all accounts. If an administrator chooses to, he or she can exclude a particular account by opening the Time Machine system preference, clicking the Options button, and in the resulting sheet clicking the Plus button, navigating to the user folder in question, and clicking Exclude.
When restoring data from a Time Machine backup, each user is limited by their account’s privileges. With a locked down parentally controlled account, for example, that account’s user won’t be able to access Time Machine (though you, as an administrator, can by modifying the account’s limits, do what needs to be done, and then restore those limits). And no user can access the contents of another user’s backed up files from within Time Machine. (However, an administrator can browse a Time Machine backup folder within the Finder, navigate to another user’s folder, and change the privileges on that folder to gain access.)
[Christopher Breen is a Macworld senior editor.]