This site reminds me of another site that has been online a lot longer: http://www.passwordchart.com/

Instead of having to store a number to regenerate your card, the card is (re)generated from a "master" password that you can memorize and never write down. You do not even need to print out your card, as you can generate your card online at any time.

I have a friend who uses this service; he has a complicated "master" password and simply uses the site domain ("news.ycombinator.com" for example) for the second field in order to generate the password to use on each site (HN).

For those who have personal policies of regularly changing passwords, just regularly change your "master" password and be sure to update your passwords on all affected sites (keeping your second field the same).