There is a legend that during the Second Punic War a large Roman fleet under the command of Claudius Marcellus was burned by Archimedes using nothing more than mirrors to reflect the rays of the sun. Whether this is true or not has been left open to debate.
Not Point Source Power has introduced the VOTO, a low-cost biomass-fueled cellphone charger and LED light. This won’t start a fire exactly, but it will use the heat from a cooking stove at a camp site to charge the battery and in turn juice up the phone. We think Archimedes would approve!