"A shop?!?" I hear you say... and perhaps your surprise is justified. But believe it or not, a shop we have. It doesn't have any Republic: The Revolution stuff, I afraid (I don't have any permission to sell merchandise), but it does have a small selection of products with the distinctive "RR" RepRev logo (see the bottom right hand corner of this page).
Each product has a slightly different version of the logo, so check them all out, and pick up a couple of things. Each sale earns me about $1 which I put towards subscriptions for various news websites from which I get some Republic info - basically, I'm looking to keep costs down.
So - take a look at the shop. New logos and a larger selection of goodies are soon to be introduced if interest is shown.