I have a few fairly complicated passwords for stuff like shells, emails, and bank accounts. For other services and throw away accounts, I usually have a constant word I use (i.e. if the login is for a game, it'd be 'videogame') and that follows by a hash i calculate of the service's name in my head. So you can do something like add every other letter's value (a=1,b=2,etc) or number of characters in login url divided by value of last letter.

This "hash" is fairly simple for me to calculate, frees up my memory and will not overtly compromise all throw-away accounts if one of them leaks.

I have a long, random password for every site, it is never the same.

I have a long pass phrase that unlocks the encrypted records of said passwords.

For most sites (most are not important) I make one note in my encrypted records and then make firefox remember them from there on out (long pass phrase for firefox master password keeper, too).

For online banks I remember something weird and arbitrary.

I do, using PasswordMaker. Plugs into browsers, runs standalone from a keychain drive, multi platform, etc. You use one main password that it combines with the site name to get a site-specific password.

I have five different passwords that I'll rotate through. Sometimes I retire a password and replace it with a new one in the rotation. Speaking of I need to do that with my email one pretty soon.

I use the same password (OK, two passwords, one high strengh, one disposable) and have a bookmarklet that hashes the password with the site's base URL. Works well for me.

i really do use a different password for every service i sign up for. here's the downside: i keep all the account records in a simple text file. i keep meaning to try out one of those password keeper apps, but i haven't yet.

i have a set of passwords that are all very similar but slightly different based on a scheme i cooked up, to make them easy to remember.

i'd probably be screwed if someone figured it out.