Sounds like a great idea!
I love the old "Corn People Make Better Lovers" and Emu t-shirts- maybe we could get some new ones for the WDW Water Society and perhaps something about the dwarf brawl? Ash grey is my t-shirt color of choice- black is too hot, and you know that white and Splash Mtn don't mix!
What about some personalized t-shirts with our board names on them? For instance, you could pick from a variety of logos (SSE, Mouse ears, Tigger, etc) and get your name embrodered below them?
I love the idea of lime green ribbons! Or maybe we could do name tags like the Passporter folks have!
Pin lanyards? Maybe a lime green notebook to jot down trip reports in? So many possibilities!