Masts, especially carbon ones. Size doesn't matter (that means if you tried to fix it loosely or cut bits of it it's still ok). Broken bits of carbon, if you have, we see.
We want to make structures and stuff with it for us (davits, windsurf trolley, spinnaker pole, brackets, seat shaft etc....). We don't have much money to offer for it but it still better than throwing it into the bin and that will pay you some beers / cookies / windsurf accessories....