I saw a neat article in a magazine about four years ago about different ideas for school valentines. Kids always come home with the same Spiderman and Hello Kitty or Mickey Mouse valentines sold at their local Walmart, and it gets a little boring after so many years.
One project that stood out, and even after four years I still thought it was cool, was to take your kid's picture, in a stance where they are holding out their fist towards the camera. Then after you print them off you make a slit at the top and bottom of their fist and slide a sucker through. It looks like they are handing their special valentine a treat.
I stood on a tall stool and angled the camera so that the kids were looking up at me, which made their fist almost as large as their head giving the photo a whimsical feel to it.
They turned out great, and the kids love them too.