Another experiment in on-line literature... theAlexandria Digital Literature library presents you with book/story/play titles; if you've read them, you rate them (at least 40 of them) -- and receive in return recommendations for books/stories/plays which you may like. This is presumably something like (but presumably not identical to!) Amazon's recommendation system. Somewhat biased towards SF/fantasy. Many books, stories, and so on available for download, for a fee.