Thanks Guy for the opportunity to re-read the Tragedy of the Commons. Tho my interest in Listers comes from my boyhood on a farm, my formal training was in biology/ecology, and first read Garratt Hardin's essay a few years after it was written. Sad to say, it is still spot on. (Check out the topic of internet flaming near the bottom!)
Unfortunately the essay and it's understanding of how human societies behave are often misunderstood today, we humans haven't changed. Many of the current tragic trends are a consequence of our ignorance of how to manage resources. (e.g., the genocide in Darfur is competition between farmers and grazers, the slave trade in Cambodia is a result of their population climbing from 6 to 14 million in one generation, the past genocide in Rwanda came from one of the highest population densities in Africa, oil wars in the Middle East, etc., etc....
Getting back to the topic at hand, WVO use as fuel is a choice, but really, the only reason they can be considered is that they are a side product of our huge, lumbering economy. If veggie oils are cheap enough, they can be used as fuel, but that doesn't necessarily mean they ultimately make sense over the long term. Yeah, I'm well aware of the CO2 argument, but they are only available because they are a waste product of fried food, (which used to be a luxury food because of the cost of the oil, until relatively recently.)
Personally, I don't use WVO because I hate working with grease, and avoid it if possible. For those with free access to it, good luck to you, but I seriously doubt that using WVO is going to save the world. IMHO, when petroleum prices make human labor feasible again, we can all get back to doing the drudge labor that employed most of our ancestors for the last 10,000 years, and our populations can again come into balance with available resources. Yeah, I'm gonna hate it too, but what are you going to do?
Meanwhile, back at the farm, if I can only fix the tractor hydraulic problem, I'll be able to unload my listeroid/generator from the back of my pickup and mount it on my foundation. Then I can finish my sawmill and look foreward to my declining years as a gentleman farmer/sawyer. Really doesn't make much sense, but it's a lot of fun!
Ray