While reading so many books, you tend to lose track of what you have read. Not anymore, Goodreads to the rescue. Here's the link if you don't already have it www.goodreads.com
Basically goodreads is designed to organise books you have read, want to read and are currently reading. You can find recommendations similar to your own interests. You can also stalk your friends and see what they are reading :)
Other users can publish reviews and all users have the opportunity to rate books they have read. The site also allows you to join books clubs that focus on specific topics i.e. comedy, romance and so on. It's also great if someone recommends a book to you, just type it into the search bar and save the book for future safe keeping. Bam, Bob's your Uncle.
I love this website because it is way more organised and easier to use compared to other sites like it. It is definitely the best I've used so far.
So if you're starting to forget what you've read; jump on the goodreads bandwagon. You will never forget a book you have read ever again :)
Here's a sneak peak at my profile http://www.goodreads.com/review/list/7819356