I just saw this listed on Kraft's facebook page so I thought I would try it and I won a t-shirt (only comes in adult large....ARV $8.25).
"Like" Jello on Facebook and then share your "happy" (download a picture from your photo albums on Facebook) on their "Happy Appy." After you have picked your picture, they will give you a chance to crop and resize it. You then hit submit and it will be added to all the other pictures. Plus, after you share it on your wall you may get a screen that pops up and says that you won a FREE t-shirt (they are giving away 1000).
One prize per email address/person/Facebook member. Ends 12/31. Go HERE to see the official rules......it sounds like there may be another way to enter if you don't win the first time.