I have a rotation of like ten different passwords, most of which are based off of a few related "core" words, with some sort of variant (so it's not just a word), followed by numbers and/or symbols. Often these are "themed", so all of my work passwords might have to do with, say, ponies or something. I also have a few different PIN numbers.

I'm usually pretty good at keeping track of it all but sometimes I forget. I started writing them all down, alphabetized by site, and it's really handy. If someone ever finds this secret list I'm probably screwed, but I like living on the edge.