I do this too! Since DD was in kindergarten, now she's in 4th! My friends all think I'm a dork, but my daughter LOVES it! She and her friends always look forward to seeing what's in the lunch box each day. I started with a post it pad in bright colors with a sharpie stuck in the same drawer that I store straws & baggies in. I would just write little things like... Hope your day is GREAT!!! Love you sugar. Then became notes she could read all by herself, then I started doing cards, jokes, small surprises, stickers or candy to share (only 12 in her class), right now we are doing our Disney countdown calendar this way. I use Mickey heads from Home Depot and write the number of days in the Mickey and the words days till... on the bottom and on the back I write things like (Getting soaked on Splash Mountain, we visit Germany, Apple Pie with Donald - Philharmagic!) We are on day 11! Today was Princess Palooza! & princess stickers to share with her girlfriends.