I like Shelfari. When I hear about a book I want to read, I can add it to my "to be read" pile on Shelfari, and when I'm ready, it'll be there to remind me.
I was just looking for a similar type of site, but for movies. Suddenly, I remembered: IMDB has that service!
IMDB lets you create a "My Movies" list where you can track the movies you own, the movies you want to see, and the movies you've seen but don't own. You can rate them, review them and organize them to your heart's content.
So, as I add Herb and Dorothy to my "Must See" list, I feel both a little foolish and a little wise.