Strong passwords are key to securing your computer, but it can be a pain to generate them. OS X has a very nice built-in password generator, but it's hidden away in /Applications/Utilities/Keychain Access.app and it's inconvenient to get to.
The nice folks at codepoetry.net (http://www.codepoetry.net) have written a free and open-source front-end, Password Assistant (http://www.codepoetry.net/products/passwordassistant), that will launch the same window that Keychain Access.app uses to generate passwords.
Launch the application, Password Assistant. You will be presented with options to create a password of varying styles (memorable, letters and numbers, numbers only, etc.), and of varying lengths (from 8 to 31 characters). As you drag the slider to select password length, you are given an indication of the 'strength' of the password.
Tip source: Password generation via a free app and built-in OS X tool (http://www.macosxhints.com/article.php?story=2010010515545381), 8-Jan-2010, MacOSXhints.com