[jester]

The natural gas vehicles in my area are very common. Most city buses and many city vehicles are powered by compressed natural gas. As well as propane powered vehicles. A freind actualy had a full sized pickup that ran on it. It had good power and only needed refueling once on the trip from California to Oregon. In college while working security patrol the company purchased several former Las Vegas Taxi cabs all running on propane/natural gas. They ran the entire weekend on natural gas, Fri,Sat and Sun, when most vehciels would need to be refueled once a day <my route required refueling twice on my own shift>

As for the digester,

A local dairy, has one. They were on a local program Californias Gold with Huel Houser. They hose down the milking room floor and it goes into a channel which flows into the pond. A cover much like a pool cover acts as the collector. The methan goes to a generator which powers the entire farms operation with surplus left over.

In Vietnam they are using methane from their chamber pots and their small pig farms to provide gas lighting and heating and cooking in the isolated farms. This I can see being more common small scale capture and production for small villages and isolated farms using limited methane prodcution.

And then of course we have Macx Max Beyond Thunderdome and Barter Town, which would be similiar to the dairy farm mentioned above, this in my mind would be a greater possibility for coops, large farms and organized villages who would be able to defend themselves as well having the manpower and of course animals to do it.