Seems like every time the temperature in the San Francisco Bay Area dips enough to actually warrant building a fire, the Air District will declare a Spare the Air Day, making wood-burning illegal. This wall-mounted fireplace from Pureflame could be the answer -- not only does it run on soot-free ethanol, I can hang it anywhere in my house.
The Pureflame runs on plant-derived ethanol that burns without creating soot or smoke. According to the manufacturer its only byproducts are steam and carbon dioxide -- both in quantities similar to what humans produce through respiration. This eliminates the need for venting or chimneys.
And without the need to vent, the fireplace can be moved from room to room like a flaming space heater. A one-quart bottle of fuel will last produce yellow and orange flames for between two to five hours. The wall-mounted varieties retail for $US650-$US880. [Pureflames via Gizmag]