Classroom B-day idea. or just a great community builder mid-year. This is seriously one of the sweetest ideas. If there is no smartboard in your room maybe you could do it with large bulletin board paper. Then they could keep the kind words.
Each teacher picks their favorite book from the book fair and then students try to guess which teacher chose that particular book. Could also say "Come take a look at our favorite books!" if you have ordered bulletin board books.