Didn't read the previous 15-16 pages and someone likely has already mentioned it but 'Deer Alert Whistles' has to absolutely top the all-time list. Particularly the 'powered' models that claim to alert the little deers much sooner than the plainjane non-powered units.
How can ya find out how much your head is worth? I didn't know they had a value.
Are you looking to sell or looking to buy? The market for used heads is a little soft right now but I can put you in touch with a Medical School in Mexico that might be interested!
I would rather wear a low profile non dot half helmet then a mushroom head dot one that feels like its going to rip my head off at over 70 mph. Unless you wear a 3/4 or full, dot's suck at speed.
You're on HDForums.com - 75% of these guys have never been to "speed."