Sometime back, [I mentioned a great little program for Windows called KeePass](http://www.allensonthe.net/2005/09/30/too-many-passwords/). If you don't use it now, you would if you had to follow [these rules](http://support.microsoft.com/default.aspx?scid=kb;en;276304)!

>Your password must be at least 18770 characters and cannot repeat any of your previous 30689 passwords.
Please type a different password. Type a password that meets these requirements in both text boxes.

(via [SecGuru](http://www.secguru.com/node/622))