My friend, Bob, is liquidating his collection of books online. He is using LibraryThing to create a database including title, author, reviews, tags, etc. I really like what his author tagcloud looks like. The more books one has by an author, the bigger the font is for that tag. If you exclude authors from the tag cloud you will see that pc_bob has mostly science fiction. LibraryThing also has a fun statistics page for pc_bob.
Here is a link to Bob’s book collection.