Yes, we have thought about having an "air bar" at events. Downside is we'd have to make sure it was pure ethanol. Gasoline is easier, because it can be a mix of many things that burn. Engines are much less picky than our livers.
You could theoretically sell devices for people to install in their back yards to brew their own fuel? Even assuming, for simplicity, the use of mains power and ethanol fuel.
Edit: already mentioned in the "How small can you scale it?" thread elsewhere.
