I think I've mentioned Library Thing in passing before. I actually signed up recently after visiting the website of one of my commentors and seeing that she was doing it.
I signed up for the thing, but there's no way I'm going to try to catalog my own books. It's not that I have so very many, but if I have any extra time, I'm going to mop the bathroom floors and paint my bedroom. Buy food. Something like that. So what I've been doing is cataloging what I've been reading because I keep track of how many books I read each year. Oh, if only I'd thought of this back in January.
Oh, wait! I've only read something like 55 books since January 1! I could take the time to enter all those. I could do it when I'm avoiding writing. Yeah! And then on New Year's Eve, I'd have a catalog of all the books I've read this year.
Assuming I wanted that.
But I'll keep trying for a while. We'll see what happens.