Someone here, in another forum (and I can't remember who to give them credit, sorry!) posted a link to this website
www.librarything.com which helps you track the books you've read. I joined (it's free) and have added some info but haven't had the chance to really check it out thouroughly yet. It looks pretty neat though because you can rate the books, write a review, and I believe enter the date you read it.
I started keeping track of the books I've read about 9 years ago because, like someone else here mentioned, I wanted a list so I wouldn't reread books I'd already read. I'm anxious to get all my info entered at librarything.com...I think it will be a helpful (and fun!) tool. Thanks again to whomever mentioned it to me originally and sorry I can't remember who you are! The link was in this person's signature.