I use the flashlights I talk about here for two specific activities.
1: Illuminating rock/ice for evening/night time climbing during the dark Swedish winter season ( example here: What did you use your flashlight for today? )
2: Exploration and photography of old abandoned mines and underground facilities ( example movie clip: http://www.youtube.com/watch?v=abAJLb_Vvnc )
I don’t do this stuff everyday, I can go for months without needing a light, but when I do I want a lot of light and don’t want to loose sleep if I trash ’em or loose ’em.