11/18/2013 Update: Important: The WSU Libraries migrated from WSU WorldCat/WorldCat Local to Search It/Primo in mid-December 2013. Griffin and WSU WorldCat links will no longer work, and if you have a WSU WorldCat account you will still be able to see your saved items if you log in to Open WorldCat (www.worldcat.org), but saved lists and saved searches in WSU Worldcat did not transfer to Search It (although Search It has something similar: see the EShelf). You can still see and search WSU WorldCat, but you'll see it is not fully functional  - click here. Summit is still functional; you can find it here.

The ultimate social tool is talking about a book (or any other kind of resource to be found in your library's WorldCat Local catalog, including journal articles). Books may already have Editorial Reviews (i.e. from Publisher's Weekly) but any type of publication can have User-Contributed Reviews (although if the item is a book it will also pull in reviews (of varyng degrees of quality...) from WeRead, GoodReads, and Amazon - see this incredibly academic example). You will need a WorldCat account to contribute a WorldCat User review. Remember that WorldCat reviews are public (if you want to make a non-public note about a book, you can add the item to a private WorldCat list and annotate it using the Add Note feature).

You can also tag a book or other item, and see all the other resources that have been tagged with the same term and other tags that have been assigned to it by other WorldCat users (at this time tags are not included in the WorldCat search algorithm).You will not see who assigned a tag to a particular item when you are looking at the item; however if you are looking at a WorldCat profile you can see what tags the user has created, and the items they have tagged with each index term.

To add a review, go down to Reviews on the item's WorldCat record, click on the down-arrow to expand the section, and click on Add a Review (you can read editorial and other reviews by clicking on the User-Contributed Reviews link). Please don't be obnoxious (inappropriate reviews will be removed).

You'll then see a page that allows you to give a quick rating (choose an option (poor, fair, good, very good, excellent) from the drop-down menu) and/or write a review. (If you can't make out this image, a full-sized version is available here.)