I have several friends who love GoodReads, Katie likes LibraryThing, and I am a Shelfari girl myself! If you are keeping a written list of the books you read, sharpen your pencils no longer! I have a virtual bookshelf which displays the covers of the books I add, I can rate, review, and make notes about the books I read, and I can save books I plan on reading. These are social networking sites so other users can view your bookshelf and you may comment on theirs.
How do you keep up with what you read?