You know... You might get some good responses from mathematicians/physicists for "desk bling" with certain products developed around mathematical constructs.

https://en.wikipedia.org/wiki/Theorema_Egregium

https://en.wikipedia.org/wiki/Three-torus_model_of_the_universe

https://en.wikipedia.org/wiki/Gaussian_curvature

https://en.wikipedia.org/wiki/Calabi%E2%80%93Yau_manifold

That last one is just for those with a sense of humor... :)

By developing a "brand" based around things like this, with good marketing principles, you might be the person that professor's buy from when trying to figure out what to get a fellow department-head for Christmas. :)