Can you picture that?
-- Dr Teeth (and the electric mayhem)
If you like playing with the Visual Thesaurus (for words) or Liveplasma for media, I have discovered a few dangerous links for readers via pixelcurious:
Literature Map will recommend authours based on the one you enter (I stumped it the first few times, but it is fun to play with)
She also recommends:
Fiction Connection: lets you search on topic, genre, etc. as well as author or title.
What Should I Read Next? : suggests books based on other reader's recommendations.
Whichbook: searches on keywords, or "character, plot, setting".