dseigler,
I am thrilled to hear you are going to use WBT in the library. Imagine how wonderful it will be when all you have to do is say "class" and they will respond "yes", and you have their attention. You will also be able to weave the rules in. For example, if someone is dawdling while choosing a book, you can remind him/her of "Rule 1- Follow Directions Quickly!"
Oh, I get excited when I think of the conversations you can have with students about authors, illustrators, characters, plot, setting, etc!
Keep us posted on how it goes!
Deb Weigel
Co-Director, WBT Model Classrooms