This little 4" x 7" book could be the most important thing you own if you have a desktop computer, laptop, smartphone, sign up on websites. Keep all of the usernames, passwords, security questions, additional notes in one location and then keep this book in a safe but handy place. There's a table of contents to organize over a hundred usernames and passwords, never to be forgotten again.
Helpful hint: Use pencil, though, if you find you need to change a password once in a while.
Price: $7.99 plus $2.25 shipping