Step 1: Materials
Pencil - Can be replaced for something longer. See above.
Bic bow and arrow - use a big thick rubber band, it makes things shoot a LOT farther.
Step 2: Bow and Arrow
Step 3: Finishing Up
Use more tape to attach the bow to the other end of the pencil. See pictures for details.
NOTE: if you wrap another rubber band around the cloths pin, you can make make the clamp stronger. if that doesn't make sense, just ignore this - its not essential. try it if you are having trouble getting the projectile locked in place.
Step 4: Loading/Firing
Load the ink cartridge just like you would with the original bow. Pull the rubber band and "arrow" back and clamp it in your clothespin (or whatever you decided to use).
To fire, just release the clamp, and watch it go!