For impromptu parties or snacks, crackers make great "bread" for sandwiches.
Between crackers of your choice, try these combos:
1)Swiss cheese and salami slices
2)Guacamole and pepper jack cheese slices
3)Pepperoni and provolone cheese slices
4)Dill mayonnaise and turkey slices
5)Roast beef slices and horseradish spread
Open face cracker sandwiches:
1) Ham slices, dab of sweet and sour sauce, and pineapple chunks (buttery crackers are best for this)
2) mozzarella cheese slice, tomato slice, and a green olive (hold up with a frilled toothpick)