Create a Time Capsule
Create a "2012" time capsule. Have kids include a letter to their future selves with information like their grade in school, Summer plans, their best friends' names, hobbies they enjoy, favorite movies, songs, and more. Also include a few mementos and photos. Be sure to seal the whole thing in an airtight container (a tennis ball can or Tupperware would work well), and wait until a sunny day to bury it in the backyard. Just remember to make a note of where it is and when you want to open it!