I don't have a lot of pins, but I have a cork board in my sewing room. I pin up what notes I need while I"m working on it and my small specialty rulers. I have the pins stuck in there.
I also have a pretty fancy pin cushion, I did keep them and other things on it for awhile, but it kept falling off the desk (it was super light) and finally I got tired of it, took the stuff off it and that's when they got stuck to the cork board.
I like your idea of doing something nice with them, for me the cork board is good enough.