In reply to Choss:
> I Remember reading about the Proper hardcore non stop 3000 mile RAAM (race across America) that some cyclists resort to attaching a bungee cord From the Back of their shorts to their helmet to keep their Neck in position.
Yeah, that's known as Schermer's Neck, not uncommon amongst cyclists doing ultra distance:
http://en.wikipedia.org/wiki/Michael_Shermer#Competitive_bicycling
I have seen people using belaying glasses for sport climbing before (especially useful on long redpoints), but I don't know if they made use of an angled mirror or a prism or what. No way I would want to use one for cycling though; you're surely not going to get much visibility with it!