The Steve Rubel Lifestream

Great advice!

Biggest drawback: you end up with one key phrase for all accounts. Still beats birthday. Alt: www.keepass.info

Or you can use an application like 1Password, works wonders for me

This is great advise to carve out passwords from sentences ! I would implement this right away,thanks :()

That's a great idea! What I like to do to remember passwords is to use a systematic pattern that only I will recognize. Just pick a word that has meaning to you, throw in a symbol character, the first three letters of the service you're using, then your favorite or most memorable number.

For example, lets say your birthday is in February, and that's the word you want to use and your anniversary day is the 6th. Your password for your Gmail account could be something like February@gma6. You can use this same pattern for you Twitter account and your password would be February@twi6, etc...You'll be using a different password for every service you have, use both upper and lower case letters, symbols, numbers, and you'll always remember your passwords for all the places you go to!

Another geeky idea. Develop and algorithm for your passwords:
http://www.dailyblogtips.com/develop-an-algorithm-for-your-online-passwords-and-never-forget-one-again/

@Jimmy: I do something similar, but with a randomly generated string of characters instead of a word. It's pretty easy to memorize a completely random 6 letter string when you use it all the time.

www.pwgen.net (or pwgen on linux) is a good tool for generating strong random passwords.