Lightly toast the bread and cut into one-inch squares (about 4 squares per slice). Spread a 1/4 teaspoon of mayonnaise in the middle of each piece. Fold the romaine leaves in half lengthwise. Cut romaine into one-inch squares along the spine, so that each square includes the spine of the leaf on one edge. Prepare 24 one-inch lettuce squares.
Cook the bacon until tender but not crisp. Cut each cooked slice into 3 one-inch squares, to end up with 24 squares of bacon.
On each decorative bamboo toothpick, skewer one red grape, one square of bacon, a fold of lettuce and a square of toast. Place skewers on serving plate or platter and serve.