For those of us who aren't hardcore night riders with hundreds of dollars in lighting, but still like to go out for the occasional night ride, this inexpensive mod might be the ticket to a little more candlepower.
I bought a Coleman Max Headlamp (model 1571) at Wally World for less than $20. This is an L.E.D "flashlight" meant to be strapped on your head (coal miner style). Output is stated as 105 lumens, 3 AAA batteries will last 6 hours on high.
I removed the headband, peeled off the rubber comfort strip and glued on a piece of Velcro, the baseplate has about the same curvature as a helmet. In stock form, there are click stops to adjust the angle of the light, but when mounting the light on the top of a helmet, the barrel must be rotated 90 degrees, making the stock click stops ineffective, some more Velcro glued to the barrel body and baseplate solve this problem. One more strip of Velcro glued to the helmet and you are done.
The light only weighs a few ounces, so I didn't notice any difference in my helmet weight wise. The on/off switch is easy to find and use, even with riding gloves on. As a test, I did a daylight run up to 90 m.p.h., the light was still attached to the helmet however, I did use an epoxy to attach the Velcro, as I doubt the self stick Velcro would stay as well attached.
Although this light is obviously not powerful enough to use as a headlight, it does put out a decent amount of light and mounted on your helmet, it will point where you are looking, making it ideal for "what was that?" situations, as well as trailside bike inspections, and checking out your campsite for creepy crawlies after the night ride is done.