Digital photography is one of those hobbies (or professions) where you can set yourself up fairly cheaply with an entry level camera, but if you wanted to, the amount you could spend on cameras and equipment is limitless! However if you're a keen photographer willing to try some DIY, there are a few pieces of lighting equipment you can actually make yourself.
Digital Photography School has made a post featuring 10 DIY flash and lighting hacks which include making your own 'poor mans ring flash' from an old milk carton, and making your own flash bouncer. I was particularly impressed by the link to the photography enthusiast who'd created a full studio lighting system for under $75.
DIY Flash and Lighting Hacks for Digital Photographers [Digital Photography School]