I have one that you can use in multiple ways...
Old hand cranked generator...
You can use it to create a spark between two wires, heat a filament to start a fire with, or you can create hydrogen and oxygen from water that you could then ignite with a piezo lighter(or just about ANYTHING else <img src="/images/graemlins/grin.gif" alt="" />)...
If you want portable, you could get one of the handheld military ones that you just give a sharp turn to and it should produce enough to get a decent spark...