That's potentially a lot of work, but I've found a simple system you can rely on to make this task easy.
Recently, Digital Inspiration proposed a simple system you can use to create a strong password based on the name of the Web site you're creating an account for. Just make your own version of this grid and print it out:
To make your password, spell out the first five letters of the site's name using this grid. If you want to create a password for Amazon:
1st letter is a: a
2nd letter is m: jv
3rd letter is a: AN6
4th letter is z: xs7
5th letter is o: enb
Your password at Amazon is ajvAN6xs7enb.
Of course, you'll want to use a password keeper of some sort so you don't have to re-enter that password from scratch each time.