I could not find any info using search so I thought I would throw this out here.
If you are a Mag-Lite user you may be interested in an inexpensive LED mod to your Mag-Lite that increases the brightness up to 7X with a 17 hours continuous run time. Additionally, produces a pure white light that really throws a beam way out there.
This page has the mod for 2-3 cell C&D Mag-Lite, $12.95; 4-6 cell C&D Mag-Lite, $16.94; and 2 cell AA for $10.95.
Ultra simple to do, just replace your incandescent light bulb with the LED module and you're done.
I just converted both my 3 cell D Mag-Lites and was more that please with the results, so thought I would share.