If you don't want to have to deal with the electrical side of things, there are some good, low weight, and compact, battery operated bicycle lights out there that use white LED technology. Cateye make some good ones, which are listed
here.
I use the Cateye HL-EL400 on my bike. It is very small but quite bright. It takes 3x AAA batteries (claimed runtime of 80 hours on constant mode - I get a lot less than this though, partially because I use rechargeable batteries). According to the website it gives out 90 candle power, and at full battery charge it is too bright to look directly at for more than a second, even from a distances of a few metres. They have brighter ones that go up to 800 candle power (HL-EL510) and even 1,000 candle power (HL-EL500BS) - these are bigger though, taking 4x AA batteries each.
Here is a quote from the Cateye website:
May 1, 2004
The very latest in white LED lighting technology
EL500 is more than twice as bright as the nearest competitor with the same bulb technology, mostly due to CatEye's proprietary Opticube lens and reflector technology. Our lights are simply the brightest.
The EL500 produces more than 1000 candlepower from a single white LED bulb, and has passed both the rigorous British and German lighting standards. The light is waterproof to 3 BAR, ensuring that it won't be compromised even in the worst of conditions.
While waterproof lights would hopefully have limited use in a workshop

, it should mean that they are largely impervious to dust.