You probably already know this one, but I'm writing it down because I always forget the water measurement. I made my jigglers in a cute little holiday mold I got at the grocery store next to the Jello packages.
1 1/4 cups boiling water
2 pkgs (3 oz each) Jello
Add boiling water to Jello powder in a bowl and stir for 3 minutes, until completely dissolved. Pour into a pan to set up or molds that have been sprayed with cooking spray. Refrigerate for 3 hours or until firm. Cut into squares if using a pan. To unmold from a mold dip the bottom of mold in hot water for about 15 seconds then invert onto a plate.