"24 Tandem Bible Storyscripts for Children's Ministry" by Steven James, Standard Publishing, 2004, ISBN 0784713200.
and
"24 Tandem Bible Hero Storyscripts for Children's Ministry" by Steven James, Standard Publishing, 2004, ISBN 0784713219.
My favorite has been the Bible heroes one. I really like the selection of Old Testament characters it uses including Abraham, Joshua, Deborah, Gideon, and Ruth. We used some of them during our VBS program and even the adults enjoyed them.
Moderator adds:
Tandam storytelling is where two characters tell the story, one is usually very straight laced, while the other is humorous, gets things mixed up, asks lots of questions because they don't understand or get the point. It's fast paced dialogue back and forth, remembering to pause anytime your audience breaks into laughter. Older children love to do these and younger children love to watch. They're also great to do during children's story time in church and we generally do them the last sunday of a rotation to share with the congregation. Adults enjoy these very much. Also note you can use these sripts with puppets as well.