Do you use LibraryThing (LT)? If not, perhaps you should. It is a social networking site that is specifically for bibliophiles. You can upload your library into LT, which is good for finding others that have similar interests to you (you can compare libraries with all the other members). Also, by uploading your books you can search your own library when buying new books to avoid purchasing duplicates, you can send a link to your library to friends and family so that they don't give you duplicates, and you can tag, rate, and review books so that others may be able to make informed decisions about buying books themselves. For example's sake here are some links to my profile and library.
On LT there are also groups that you can join. An LT group is a set of users who have voluntarily joined together to compare libraries, share tips, deals, etc, and to talk about other things via the forum feature. I'll list a few here that readers of this blog may be interested in: Ancient History, Bible Collectors, Bible Scholarship, Biblical History, Bibliobloggers, Christian Mysticism, Christianity, Church History, Faith and Reason, Graduate Students, Hebrew Literature, Jewish History, Non-Fiction Readers, Scriptures, Seminary Students, and Theology 101.
Go and sign up! There is a free membership option! You know that you need another reason to spend time on the interwebs!