Password machines are just part of the Yugioh! Video Game family. Although I do like the ones where you have to have 1 copy of the card in your inventory for the password to be available for use. Like Spirit Caller (you have to beat the game before you get a Cyber Dragon!). It allows you to "trade" DP for whatever card you want, although at quite a hefty price.
But I have heard of 2007 having a feature which allows you to Download a new banned list. That is awesome! Makes the replay value much better. As for me, I'm still playing through spirit caller and haven't really started on WC07 yet. Soon though, and then we will duel.