A few years ago, when I was just starting out with photography, I posted a set of instructions to make your own Better Beamer flash extenders. Essentially these are large lenses placed in front of the flash bulb to focus them onto a tighter spot, so that the flash can reach incredible distances. Think of it as your flash zoom head on steroids!
Materials: The main materials you will need are a large fresnel lens (used as reading aids for poor-sighted), some rigid material to hold the fresnel, and some velcro to assemble the whole device. Details below!