The first site I looked at was LibraryThing, but was put off immediately by the language used to describe the site and how it works, which came across as anal-retentive librarian (apparently, I'm not allowed to make any further comments on this). Next up was Shelfari, which has had some bad press for security lapses and didn't look over-interesting, so in the end I settled for Goodreads. The UI of this site was the most appealing, but after 24 hours, I'm still struggling to make it do very much other than sit and look at me. Presumably the problem is that I don't have any friends on the site, so it's going to take a long time to build yet another network whose interests and tastes overlap my own rather eclectic choices.
Anyone used Goodreads or have other recommendations?