I thought about building this some time ago... and I'm glad Petzl finally did it: headlamp that limits power when you point it to something near, such as map. Petzl Nao seems to be interesting piece of hardware. I'm not sure if they are capable of modes I'd include... I'd include 1 micro-W mode, useful for walking in the forest with eyes adjusted to the darkness, still good enough so that branches do not hit you in the eye. And I found that cca 10mW mode, where you can approximately see meter or two before you and still keep some night vision is useful, too. In general, "put out as much light as you can without affecting night vision" would be cool, but I'm not sure if that's easy with current hw.