Shrinky Dinks are these excellent thin plastic sheets that have patterns on them you cut out (like Smurfs or Superfriends, etc) and draw on in color pencil. You then put them in the oven (at 200 degrees?) for a few minutes and they shrink and get hard, so you can play with them.
In reality, I can't recall ever having fun with the completed project, but it doesn't get any better then watching them shrink in the oven.
Thanks!