I see a lot of you carrying these...any special reason?

I mean...is it the novelty or true function?

re: the carrying of spare bulbs for LEDs. I do this in a few lights. For instace, while I changed over two of my 3D mag lites to MaxStar5 - 5 Watt Luxeon TLE-6K2 LEDs (from batteryjunction.com), I also have Mag drop in LED replacements as my spares in the cap should something ever happen (probably physically) to the primary bulbs.

But, in other areas I have different LED lights.