That way, when you type it into one of those secure password entry dialog boxes, you'll be able to read it in cleartext, and see you're not making any errors! And since this won't occur to the bad guys, you'll still be perfectly safe!

Note:

Extremely advanced computer users will note that many advanced computer applications use asterisks and not X's to display your password. Such advanced computer users are advised to pick a password with only *'s in it (and learn to use the shift key).