My kids and I had fun with a spray bottle and a propane torch. The bottle contains diesel fuel, so I would hold the torch in front of bottle, spray fuel and it would erupt in little fireballs.
I would like to find something that would be compressed air powered, and would spray a jet of atomized fuel. Ideally it would be some common air tool or a common component. I have for now considered paint guns, as well as a engine cleaner air gun, but perhaps there is something more suitable. The engine cleaning guns usually pick up way too much fuel.
i