Here is a gadget that would have saved me a FORTUNE in face shields if I'd found it five years ago.  I always carried three shields for my helmet - a clear, an amber/fog, and a tinted sunshield.  The Shoei quick-release design made it a snap to switch shields (even without taking the helmet off once I got used to the mechanism), so I always had the proper face shield in my trunk for any riding conditions.

The problem was, that I simply stacked the two shields that weren't on my helmet in the trunk, with a polishing cloth between them to "protect" them from scratches.  Believe me, it didn't work - my shields would barely last a season before they were so scuffed that I couldn't stand them.  At $35+ a pop, that adds up!

These Face Shield Protectors are form-fitted to protect most popular brands of full-face helmet shield (Shoei, Arai, etc. - full-face or flip-face only, not 3/4 or shorty helmets) and are made of soft neoprene to keep them protected from scrapes and impacts.  Available in three colors, so that you can tell your shield from your passenger's.  At only $12.95, they also make a great gift for the "motorcyclist who has everything".