Cut both limes in half lengthwise. Scoop out all the fruit with a spoon. Place the limes in a muffin tin to keep them from tipping over. Make the box of Jello according to the Jiggler directions. Carefully spoon Jello into the limes halves. Chill until almost firm. Using a skewer push the mini chocolate chips into the Jello for "watermelon seeds." Chill until until firm, then cut into slices.