MEME: Booking Through Thursday

Do you use any of the online book-cataloguing sites, like Library Thing or Shelfari? Why or why not? (Or . . . do you have absolutely no idea what I’m talking to?? (grin))
If not an online catalog, do you use any other method to catalog your book collection? Excel spreadsheets, index cards, a notebook, anything?

I use librarything, and I'm raidergirl3 there as well. I use it to catalogue the books I've read, and some of the books I want to read. I read a lot from the library, and this is a way to keep a record of those books as well. I am having fun there, and the forums are interesting and very specific at times - you can find someone who wants to talk about whatever you want about books if you look around enough. I didn't realize it had such an interactive component to it.

I bought my first online membership there, and it felt rather scandalous to pay to find pictures of the books I've read and to tag and catalogue what I've read. But for now, I am having fun, so why not?