Amazon has a cute set of veggie cutters currently priced at $3.25 with FREE shipping! You can use these to cut shapes from veggies and fruits!
Another way to use them is to cut shapes into graham crackers. Spray the graham crackers with a bit of water and microwave for 40 seconds. Then cut your shape! Be sure you save the little cut outs for other treats. You could add a dab of peanut butter between two cut outs and make mini peanut butter sandwiches!
Graham image and tutorial: Cute Food for Kids