I'm baaack! Some of you guys have built some neat lights, ie the light head itself, but for those intimidated by that prospect or don't wish to re-invent the wheel, check out the Optronics QH-7CC and QH-8CC driving lights. They cost about $16 per PAIR and use MR-16 bulbs. I prefer the 8 because is has a black plastic body. The 7 is a chrome metal body. One slight issue with the plastic body is that it has ventilation slots what could allow rain to fall right in when the light is mounted up as I do on the bar. I have solved this by fashioning a simple "hood" from black electical tape that leaves the vents open but prevent rain from falling straight in or running in. The chrome bodies have a simple twist off front that makes bulb changing easy. The plastic body uses two tiny screws so is less convenient. I have tried both in my experimentations. Here is a link:
http://www.optronicsinc.com/competition.htm
These are small, lightweight lights that have a nut and bolt mount. All you have to do is fashion a simple mounting method. On one bike I am experimenting with 3" spring clamps from Lowes. The have a hole so you don't even have to get out the drill. The clamp can be difficult to squeeze open to get on the bar, but with a piece of inner tube to protect the bar it is pretty secure, easily adjustable and a quick release. The lights come with 50W bulbs which is a bit much for the smaller 4 to 5 AH batteries we all seem to be using. I have found two bulbs that I am very happy with. My favorite is the Solux daylight lights that have a very white light that provides super visibility. The lowest wattage is 35W so I use it on a bike with a 7AH battery and no rear lights yet. These bulbs cost about $6 or $7. Another great bulb is a Phillips energy saving bulb that produces 35W of light with 20W draw and costs about $10. This is working great on my bike that has two rectangular 8-LED truck/trailer marker lights that also have reflective lenses and draw almost nothing. They are available from LED-R-US. Even with the lights off you have a reflector. The two MR16 bulbs are more expensive than standard $3-4 bulbs, but I think they are well worth the price, especially when you consider that they are rated for thousands of hours, or several years, of 1 hr/day commuting. BTW I tried narrow spot bulbs initially, but have gravitated to wide 36 degree floods because they provide plenty of light out front as well as plenty to the sides. The spots were great out front, but I couldn't see the side of the road. It was a bit claustrophobic.