Last year when I went to Carlsbad Caverns with my family I took my Mini-Mag Flashlight with the TerraLUX TLE-5 1 watt LED Replacement bulb.
This LED last 5-6 hours in the 2aa Mini-Mag and produces a very bright 50 Lumens of light. Here is a link to some pictures I took in Carlsbad Caverns using the TLE-5 LED for lighting of the formations.
http://www.led-replacement.com/blog.html
We also have screw base LED Replacement bulbs for 2,3 and 4 cell headlights (bottom contact must be positive) http://www.led-replacement.com/screw_base.html
Thank you!
led-replacement
http://www.led-replacement.com/index.html