I picked this "Sterno" type fuel up at a dollar store near the Mexican border town of Palomas. After testing it twice, I've decided it works wonderfully for a simmer, or if you're not in a hurry. The beauty of it is you don't have to keep adding fuel, you can put it out instantly by replacing the tiny metal cover, the source burns nearly odor free and you know exactly how much is left. Unlike canister cooking, once the fuel is gone, this metal container will be a useful piece of equipment.
According to the label, this fuel will last 2.5 hours.