Doh, I completely forgot to mention Shelfari.com It is pretty similar, you post the book(s) you are reading, the books you have read, and the books you want to read.
Thanks for posting your list pilotbob, it is interesting to look through and get ideas for what I want to read
I would post my list from Shelfari, but unfortunately I just haven't had the time to sit down and add all the books I have read... I should stop being lazy and do that one of these days.