Putting my Talis' money where my mouth is, I've set up a SemWeb T-Shirt shop in coordination with the W3C Communications team (which, btw, is working on an official W3C shop :).

The Community shop features a couple of cube-based designs, but it's also meant to support the broader SemWeb Interest Group and their members' open-source projects. I'm happy to help with designs and product creation (as time permits). Profits will go straight to the respective project maintainers.