Reposting from other passwords thread as I feel it's relevant here also:

Why do people insist on having short (<12 chars) overly complicated passwords? The passphrase: "totallysecretpasswordthatyoullneverguess" (or other similarly-long phrase) serves as a much more secure pass-phrase than the hodgepodge of non-alphanumeric characters people suggest that good passwords are and is far easier to remember. The only impediment to decent passphrases are services that limit how many characters your password can be.