I use a form of the Vigenère cipher cipher that is simple enough that I can 'get' my passwords with a pen and paper (I've had to do this before for public terminals), but is also made less cumbersome with a simple little utility.

It isn't cryptosecure or anything, obviously, but it works well for my purposes. I've never been entirely comfortable with using someone else's web site or a password database (well, I use a password database at home, for example, but I have to have access to passwords remotely).