how to refine a topic and its searches; updated for web 2.0 and specialty searching; good for anyone starting to do Internet research on a topic and will take you to some previously unused search tools
You sign up, enter the name of a book, then find out what other folks who liked that book also liked; a tag cloud for the book leads to other books on this topic. Quite addictive, and I just used it to look at the info. around one book.
CiteULike is a free service to help academics to share, store, and organise the academic papers they are reading. When you see a paper on the web that interests you, you can click one button and have it added to your personal library.