Joel Spolsky wrote a short article: Password management finally possible
…there's finally a good way to
manage all your passwords. This system
works no matter how many computers you
use regularly; it works with Mac,
Windows, and Linux; it's secure; it
doesn't expose your passwords to any
internet site (whether or not you
trust it); it generates highly secure,
random passwords for each and every
site, it's fairly easy to use once you
have it all set up, it maintains an
automatic backup of your password file
online, and it's free.
He recommends using DropBox and PasswordSafe or Password Gorilla.