Two RA forums I hadn't heard of...

You learn something every day!

1. AbeBooks BookSleuth®: "Is there a special book that you read, or perhaps had read to you, at some point in your life but you can't remember the author and title? Perhaps you know the plot, or a character, or maybe even what the front cover looks like. BookSleuth® is here to help you find that book! Simply post a short description of what you can remember here on our board. Visitors from all over the world will read your post, and one of them is bound to know exactly what you're talking about and post a response. Not missing anything? Why not see if you can help anyone else find their long-lost books?
2. LibraryThing group: Name that book