In that case I would probably be wasting my time by posting http://www.bikeforums.net/electronic...50-thread.html then...

If you're looking for something to 'be seen' during the day and 'see by' at night, it really is hard to beat a flashlight powered by a 18650 cell. You could use an AA powered light, but the cheap ones aren't as bright or last as long as the 18650 lights and the AA ones that can hold their own against the 18650 ain't cheap.