Making your own tools and equipment whenever possible is not about saving money. As a matter of fact, many times one can ebay at half the price of what it would cost to make it. Instead it has to do with keeping your creativity in shape and -more important- sharpen your combinational skills and imagination. You need something, you need it NOW, you look around, you find parts, you combine, you create.
This is what phpenguin did. With a few pieces of wood and two lamp holders he made his own work lamp. It can be mounted on any flat surface with a C-clamp and has three wooden side reflectors covered with aluminum foil.
A few more images here