Every week, there are dozens of breathless new ideas about how to make use of the internet. Now and again, there is a real gem with tremendous potential. I believe that Library Thing is just such an idea.
Type in a few words from the title of a book in the search box and hit "Enter". The site searches Amazon and the Library of Congress catalogue as well as others. You then select the item which matches the book on your shelf and it is added to your "Library". All the details are included - author, title, date, publisher ISBN etc. It is amazing how quickly it is possible to catalogue a dozen or so books. You can export your "Library" to a file, import from other files, put a widget on your blog etc. The service is free for 200 books and after that it is $10 per year or $25 life membership.
I'll be using this big-time as it is the first practical answer to cataloguing me library without taking a six month sabbatical. I will be doing a shelf at a time. Going through the first Patristics shelf, I found that one or two books didn't show up but I was surprised at how many did.
This site is likely to be a big hit with Catholic bloggers who seem mostly to be quite avid bookworms. Very grateful hat tip to Dilexit Prior at Letters from a Young Catholic.