Another Schneier recommendation is to write your passwords down, just keep the piece of paper away from people who might misuse it:

http://www.schneier.com/blog/archives/2005/06/write_down_you...

I have about 30 unique passwords which I keep in an encrypted file, and a password for "everything else". I have about six passwords I can remember off the top of my head and two of these concatenated are used to unlock the encrypted file. I would seriously recommend doing something like this: you'll feel much happier, I promise.