Long passwords are easy
...as long as you stick to words, and use more than one.
I used a similar scheme to the one you describe, and then I read this (posted by another El Reg forum user a few months ago):
http://xkcd.com/936/
I'm not ashamed to say I was embarrassed by this revelation, and have started to apply the principles to my passwords. Unfortunately a lot of sites insist on relatively short passwords.