If you start singing the praises of multiple identities to your psychotherapist, you’ll definitely get her to sit up and take notice—and probably not in a good way. But make the same comments among a group of Microsoft Office power users and, if you get any response at all, it will come in the form of a knowing nod or an agreeing grunt. When Microsoft refers to multiple identities it’s talking about an Entourage feature that lets several members of a family, school, or work circle use the same program on the same Mac—but maintain independent calendars, email accounts, mailing list info, rules, messages, preferences, signatures, to do lists, address books, and so on.
You’ll find reference to these identities throughout the Office 2008 suite. For example, the currently selected Entourage identity is the source of names for the AutoText feature in Word, as described on Setting up an AutoText entry. (That’s also why you can’t edit or switch identities while Word, Excel, or PowerPoint are open. They depend on the currently active Entourage identity for some of this information.)
To some extent Mac OS X makes the identities feature obsolete. After all, it’s typical now for everyone who shares a Mac OS X machine to sign in with a name and password—and therefore each person’s mail, calendar, and other information is already separate. Still, there’s nothing to stop you from using Identities on Macs configured with but one user account (because it’s just you and a spouse, say, with no secrets from each other), or when you want to create different identities for yourself (a Work and a Home collection of email, for example). For more detail on handling multiple users and identities, see the box below.
UP TO SPEED: Identities vs. Multiple Users in Mac OS X
Identities are for convenience, not security—that is, they’re not guarded by passwords. Anyone sitting in front of your Mac can switch among your Entourage identities at will, read your email, modify or delete your contacts, calendar items, or even delete your identity altogether.
To protect your data with a password, you should set up individual accounts for each person who uses your Mac, instead of using Entourage identities. At its core, Mac OS X is a multiuser operating system, and each account holder has his own desktop, Documents folder, programs, bookmarks, music and picture collections, and more—all of which can be protected from other people who use the same machine. You set up user accounts in the 
→ System Preferences → Accounts panel. See the Mac OS X Help menu for more details.
If you’ve already set up identities in Entourage before you’ve created Mac OS X user accounts, more work is involved to move one of those identities into your newly created user account. Each identity that you’ve created is represented by its own folder in the Home → Documents → Microsoft User Data → Office 2008 Identities folder of whoever first set up Mac OS X.
To straighten out your folder setup, you can move the identities to other Mac OS X users. First, log in as the Mac OS X user who has the Entourage identities you want to move. Find the appropriate identity folders within your Office 2008 Identities folder, and then drag (or copy) them to your Home → Public folder.
Next, log in from your new account. Then navigate to your Public folder and copy the appropriate identity folders to this new account. The next time each of these Mac OS X users opens Entourage, the copied identity will be in place, revealing only that person’s email, calendar, and so on.
When you first set up Entourage, you get a single identity. (Of course, you can have multiple email accounts within that identity.) To create a new identity, proceed like so:
Quit all Microsoft Office programs except Entourage. In Entourage, choose Entourage → Switch Identity (Option-⌘-Q).
(Just be careful not to hit Shift -⌘-Q, which logs you off your Mac!)
Entourage asks you if you really want to switch identities.
Click Switch.
The identity management window opens (Figure 11-33). In this window, you can create, rename, or delete a selected identity (or quit Entourage). Be careful before you delete an identity. Once an identity’s gone, you can’t retrieve any of its information.
Tip
If you turn on “Show this list when opening Entourage,” Entourage gives you a tidy list of identities each time you start up the program, making it easy to specify which identity to use for that session.
Figure 11-33. Any identities that you create in Entourage show up in this window. Use the three buttons along the right-hand side to create a new one, change a name, or delete an identity you’ve outgrown. When you delete an identity you delete all of its Entourage data: messages, calendar, address book, and so on.
The small New Identity window pops up.
Type a name for your new identity.
Choose a descriptive name for the new identity.
Follow the Entourage Setup Assistant.
Once you’ve chosen a name for your new identity, Entourage asks you if you want it to be your default email program. Your reply here actually changes a system-wide setting in Mac OS X, so this choice will apply to all your Entourage identities.
After you choose Yes or No, Entourage walks you through the Entourage Setup Assistant to create your new identity—a process identical to what you did when you first set up Entourage (see Setting Up Entourage). When you’re done, Entourage opens its main window, displaying that familiar “Welcome to Entourage 2008” mail message in your new Inbox.
Figure 11-34. Anytime you want to find something in one of Entourage’s list views, resist the temptation to just start scrolling through the list. Instead, type a few letters of what you’re looking for in the Quick Filter and let Entourage swiftly sift a few likely suspects from your prodigious stockpile of information.