The 'Bird at a local Cruise-in.
Legendary comic strip.
This is what a xenon arc bulb looks like. There is no filament. The light source is an electric arc, or plasma, arcing between the two electrodes within a nobel (inert) gas contained inside the tiny glass bulb. Variations in light color are achieved by small amounts of impurities in the gas.
Xenon lamps are also environmentally friendly form of incandescent lamps with long life times, minimum heat generation, less energy consumption and no mercury. If you hate lighting your home with CFL's you might want to pay the higher cost for xenon lamps. In the long run they actually cost less due to longer life and lower energy cost.