LibraryThing is a social library catalogue. You can create your own catalogue of the books you own by entering the title or isbn or searching some other way, then ‘tag’ them with your own keywords, rate them, and even write a review.
But the real fun comes from clicking on a book’s “View social information” icon to see how other people have tagged, rated, and reviewed it, what discussions it’s being mentioned in, and “People who have this also have…” (LibraryThing even has a fun “People who have this *don’t* have…” feature.) You can even include a widget on your blog or other website to show what you’ve been reading recently.
What relevance does this have for libraries? LibraryThing for Libraries lets libraries add any/all all this functionality (tags, ratings, reviews, similar books) into the library catalogue. See examples at Pelham Public Library and California State University.
Enough introduction – the thing of the week is to create an account on LibraryThing (reuse your blog username and password!), add half a dozen books, and… explore.