LibraryThing

If you haven't checked out LibraryThing yet, take a look. It's an incredible resource for writers and readers to connect through their book holdings, interests, recommendations, etc. For example, I searched language poetry and retrieved a list of books tagged as language poetry, a list of the people who tagged them, a tag cloud of related tags, a list of related terms, and the last ten books tagged as language poetry. At 16,000,000 plus books, LibraryThing is becoming a very potent online tool.