more important...don't forget the tool you carry IN your helmet....your brain...learn to use it....keep it honed and sharp...it will never let you down when you need it if you exercise it regularly...
including my brain, i carry a window punch and 2 "cherry bombs", a surefire light with a blackjack mount and i picture of my wife and baby on the inside.
I am looking at a new helmet light. The type that hasa elasitic band to mount it in the front.I used to have a ton of chit on my helmet but I didnt like the unbalanced feel and moved the stuff to my pockets. I miss haveing a helmet light i used it mostly on overhaul and mva's.