Over at the SANS website, they have a security awareness tip of the day page.
This is a great idea if your password field is not limited to just 16 characters. Try it next time you need to change.
September 24, 2009
Change from a password to a passphrase
It's better to use longer and more complicated passwords, but they are hard to remember. Try using a passphrase like "I love getting to work at 8:00!" It's long, easy to remember, and has a mix of upper case and lower case letters and symbols. Don't use familiar or famous quotations. Don't use any real names, especially your own, your family member's, or your pet's. Nonsensical passphrases are the hardest to crack. Because password cracking time increases exponentially, a criminal with substantial computing resources can crack short passwords quickly; while a 31-character (the length of our example) passphrase would take 231,935,475,118,605,000,000,000 years to crack! Best of all, it's easy to remember.