On my computer desktop, I have a file named "Books to be Read." As I wander around the Blogosphere, I'll often find a book review for a book that sounds interesting, so I'll open that file and jot down the title. It's not that I think I'll ever really read every single thing on that list, because I add several books to it a week, but it's so nice to have a whole file of books that someone else has read and recommended. It makes me feel like my odds of scoring a good read have gone up several percent.
And, because it's a computer file, it's easy to go in and delete books once they're read, and to print it off when I'm out the door to the library.
The only thing I would do differently would be to write down where I saw the book reviewed. Yeah, that would have been good.