I keep a list of all our books in Word, so I can print it when we're in the UK, to refer to in second-hand bookshops and charity shops. With the number of books in our household, I often can't remember (for instance) exactly which Agatha Christies we have already.
I've always liked the idea of making booklists available online, with short reviews. I've written longish reviews on Ciao and Dooyoo, and the occasional shorter one on Amazon UK. A few years ago I built a Geocities site for reviews of all the books I read, and then when I began blogging, started a book reviews list there - which I backdated to include everything from the start of 2005. That was a great deal easier than trying to maintain a site. But I also felt I wanted somewhere to list ALL my books.
Two or three different bloggers mentioned Library Thing, which seemed like a good idea: a place to catalogue and share lists of books. The only problem is, it charges a fee for any collections over 100, and I'm always rather reluctant to pay fees for something like that. Yes, I know it costs to maintain sites and I have no problem with optional donations - but in general the Internet is free, with paying options only for enhanced use. 100 books is almost nothing so it felt like only a 'demo' edition available free.
Next I discovered AllConsuming, a site where I can enter in the titles of books I'm reading (or have read) or movies I've watched, or even food I've eaten.. with possibilities for rating, reviews, and so on. It has a link to attach to the side of blogs, which was a good feature - my current reading should be displayed somewhere in my side-bar on both this and my book reviews blog. But it doesn't have useful ways of sorting the lists or easy way of comparing with other people's lists.
Then I saw a link to Bibliophil on one of the blogs run by a long-standing email friend Steve, aka Methodius. I followed the link, and there it was - exactly what I was looking for. Cataloguing of books using information from Amazon, no limit to library size (though optional donations are welcome), and several interesting features. Moreover the site author is clearly active and updates it as he thinks of new features.
Of course, even with broadband it's quite time-consuming entering books - and so far I haven't done any reviews. I haven't even rated most of them. But if I do about 50 per day, I might have our entire collection entered by about the middle of March....