A good friend linked me to this slightly unbelievable video, which demonstrates how to make a apparently very usable black and white film developer using just coffee, vitamin c power, water, and a little washing powder (via a post on Engadget).
It looks incredibly simple, and the results that the narrator seems to achieve are almost suspiciously good. You’ll still need conventional store-bought fixing chemical, of course.
I have personally been paying around £18 a litre for Ilfosol DD-X. I push practically all of the black and white that I shoot at least 2-3 stops, at which DD-X excels. This home-made processing chemical (which users have apparently named ‘Caffenol’) might make it worth shooting a roll or two at ISO 200 or 400 just to see what sort of negatives it produces.