In this article Mohamed Talal shows us how to make a simple diffuser for a DSLR pop up flash.
There are three things that separate this diffuser from other diffusers we have featured before. The first is the total cost - this one really costs nothing. The second one is the size of the diffusion panel. By using this method you get a nicely sized diffusion panel. Lastly, a quick mod will turn this diffuser to a ring flash.
It is called the Headphones diffuser, but don't feel obliged to use headphones casing, you can use GI-Joe's casings, Transformers casings, or just a nice pieces of transparent material.