In this lesson on WorldCat I created an account and started fiddling w/all the options.I made a list of my Favorite Mystery Writers and I'm now watching 3 lists:
Cozy Mysteries, Lefty 2009, and Edgar Allen Winners. I chose to RSS feed the Cozy Mystery list and Tweeted the Lefty 2009. There is now a review for Girl with the dragon tattoo http://www.worldcat.org/oclc/226304725. The lesson covered most of the library/patron uses for WorldCat, at the moment I can't think of anything else.