By using popsicle sticks and some glue you can build yourself a clever little trebuchet. This is a good replacement for the one made out of paper that has vanished from the Internet. You will need 18 sticks for the frame sides. Start by squaring off the ends of 6 sticks. 2 sticks will form the uprights (part 1), and 4 sticks will form the base fore and aft of the uprights (parts 2 and 3). Thanks John! Link.
Make a desktop trebuchet