What Should I Read Next? will help you find other books & authors that you might also like.
Whichbook uses a set of sliding scales between opposing concepts that allows you to indicate how much of a given quality you wish to have (happy/sad, gentle/violent, easy/demanding) in your reading and provides a list of books which contain the element(s) you have chosen.
Book Army is a social networking tool for readers. You can write reviews, share book lists and communicate with other book lovers.
(adapted from Kevin Purdy's Top 10 Tools for Better Reading Online & Off )