Tina R. reviewed Clever Letters: Fun Ways to Wiggle Your Words (American Girl Library) on
Mine 9-year old daughter loved it. It has ideas about other ways to create "secret" messages, like wrapping a strip of paper around a pencil, writing the message, removing it, then the reader has to have a pencil to determine the message. She's had lots of fun with it. I thought it would have more tips on ways to form funky letters, but it's more enjoyable to my daughter this way.