Spotback gives the new comers a three step flash based tutorial. Click the top right "get started" link on the Spotback homepage to see it. They're showing the newbies how to rate a story with their rating slider. How to add/remove categories in order to choose your preferred fields of interests, BOOM - notice how the "More stories" starts to blink in red. Yes, thats the third feature. Click it to see additional stories based on your rating history. Pretty simple stuff but nicely done. Read more about it on the Spotback blog.