Strong (long) passwords

REMINDER: PASSHPHRASE SHOULD BE 24+ (42+) CHARACTERS LONG TO BE EQUIVALENT TO A 128 (256) BIT KEY.

This xkcd comic brought forth a lot of discussion on the internet regarding how to choose your password. What I took away from it: it's better to have really long passwords than to have short, complicated passwords. This post describes a reasonable system on how to set up your passwords. Basically, group your services into tiers that require different levels of security. Then set up long passwords that you can remember. Thanks to the comic and the aforementioined, I've come up with my own system of secure passwords. I won't describe it due to security reasons =].