I shared a fun idea here where you purchase the book, "Oh The Places You'll Go" (secretly from your child) and each year at the end of school have their teacher sign the book with a little sentiment about the child. At their graduation, hand them the book and they will have fun reading through the comments and well wishes from their teaches over the years! Plus it is a fun book!
Here are some nice deals on the book:
Target - on sale (through 3/1) $10 Plus, use your redcard to save an extra 5%, so as low as $9.50!
Oh the Places You'll Go!: Dr. Seuss Happy Graduation Gift Set - $12.02 at Walmart or grab just the hard cover for $10.48