Hide/unhide accounts in Mac OS X's login window

I found an article at macworld which shows how to show or hide users in Tiger's login window. To summarize:

Hide users:
sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add account1 account2 account3

Unhide users:
sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add

(where accountN are the short names of the accounts to be hidden).