Story Starters -- Join the fun. Read the introduction to the story, then post your ending in the comments section for everyone else to enjoy. There will be a new story starter every couple of weeks, but since this website is new, you can get in with Volume 1.
PaperBack Swap -- If you're looking for an easy way to clear out some of your books and get new ones cheaply, give this website a try. Here's the link to my personal list of books posted on PBS.