The neat thing about StumbleUpon is that once you train it (a half a dozen stumbles) it will take you to content that you are pretty much guaranteed to like & enjoy. Whether it’s finance, arts, ancient history, writing, blogs (some of my personal favourites). Just give it 15 minutes – it brings back that joy, that sense of discovery that we have lost with information overload.
Amazon also does this for books. Last.fm does this for music. What could you do it for?