way, way kewl... wisht Iduh had somethin' like that... we usedtuh strap mini mag lites to our helmets with innertube bands, but these are hi-speed...
Another, less expensive, specialized light is make by Pak-Lite. It's so minimalist, it might get lost. As a plus, it would be a good item for an emergency kit.
It's biggest advantage is that it comes with LEDs in all sorts of colors, including infrared. In fact, you can get the light in two different IR wavelengths, with and without a strobe function. For CSI fans, you can also get it in ultraviolet, so you can do your own forensic studies.
At about $29, it can be used as a short-range IR illuminator, or the strobe version can be stuck behind the helmet camo band, and used for IFF purposes.