Two years ago I added a Shelfari widget to my "Relatively Fiction" blog:
My Shelfari statistics indicated that I've logged 182 books in the "I've Read" category in the past two years (mostly mystery books with a few history-related books thrown in for good measure). There's only 3 books in my "I Plan To Read" category (actually I'm probably hauling about 50 around with me in the motorhome RV). There are also other categories available on Shelfari, including a "Wish List."
Organizing is one of my weak suits, but Shelfari helps me. Buying duplicate copies of books at used book stores is less of a problem because of Shelfari. Thank you, Shelfari!