The account system described so far in this chapter has its charms. It keeps everyone's stuff separate, it keeps your files safe, and it lets you have the desktop picture of your choice.
Unfortunately, it can go from handy to hassle in one split second. That's when you're logged in, and somebody else wants to duck in just for a second—to check email or a calendar, for example. What are you supposed to do—log out completely, closing all your documents and quitting all your programs, just so the interloper can look something up? Then afterward, you'd have to log back in and fire up all your stuff again, praying that your inspirational muse hasn't fled in the meantime.
Fortunately, that's all over now. Fast User Switching—a feature modeled on a similar Windows feature, which itself was modeled on a Unix feature—lets Person B log in and use the Mac for a little while. All of your stuff, Person A, simply slides into the background, still open the way you had it; see Figure 12-14.
When Person B is finished working, you can bring your whole work environment back to the screen without having to reopen anything. All your windows and programs are still open, just as you left them.
To turn on this feature, open the Accounts panel of System Preferences (and click the , if necessary, to unlock the panel). Click Login Options, and turn on "Enable fast user switching." (You can see ...