Memory Tools for Password Management?

New Media Blogger asks: "A co-worker of mine recently got burned hard because they used the same password for all of their online accounts. This experience led me to compile a list of easy-to-use password management memory tools (all free, of course), which make it infinitely easier for me to keep track of my dozens of passwords. I am sure many of the Slashdot crowd have memory tools of their own — what are you favourite password memorization tools?"