[QUOTE=NeilBlanchard;206604...I recall a news story about the good folks in Bradford PA growing sunflowers in vacant lots to make biodiesel.[/QUOTE]
Sounds like an interesting plan - using otherwise unused properties to make biofuel, teach about gardening/small farming, etc.
I wonder how much oil they manage to make. According to this site:
Vegetable oil yields, characteristics: Journey to Forever
you'll only get about 102 gallons out of an acre of sunflowers - If the squirrels don't get to them first!