I have 2 Library Things I contribute to; it took me a while to realize that if I don't sign out of one of them then that will be the one which comes up each time, and I won't be able to get into the other one even though I can see it. The old bad dream thing where you are in a cage and can't get out.
Or like my friend who I recently visited who has only just realized after 8 months that she has 6 gears on her car!! Well, she's never had a car with overdrive before!
Anyway, they make it very easy for you and it's been especially useful for a book group I belong to. We don't have to email a list out any more and if someone is away from the meeting they can still enter reviews. I may suggest starting one for the other book club I belong to but probably not to cover the backlog.