How do you Remember Your Passwords?

Aaron asks: "Like most people reading this, I have more than a few computer accounts. Password maintenance (e.g., changing them regularly, thinking of ones that are hard to crack but possible to recall, remembering what this week's password is on account foo) is nontrivial. What strategies for managing passwords do you have?" Mnemonics and password schemes are tricks a few people use, but I'm sure some of you out there have better ways. Would any of you care to share?