This fellow here, Mark Boyle, is living without cash for an entire year. Living in a camper on a farm he uses a stove outside to cook on rain or shine, a bike to get around on and a solar powered laptop to stay connected to the world. For food he finds it, grows it, or barters for it. He wipes his ass with newspapers and brushes his teeth with ground cuttlefish bones. Hardcore.
I have always really loved the idea that you have to be the change you wish to see in the world so I find this pretty inspiring. He is also the founder of The Freeconomy Community.
Here is an article from the Guardian all about it.