I think that opaque glass walls are the best. My office has opaque glass walls on two sides which, in addition to making good writing surfaces for dry-erase ma

I think that opaque glass walls are the best. My office has opaque glass walls on two sides which, in addition to making good writing surfaces for dry-erase markers, allow me to see the fuzzy outline of people as they walk by my office and allow me to see when other people are in their offices (as the glass walls will light up.) The opaque glass walls provide a sort of literal privacy that cubicles or open office spaces don't (such that I don't have to guard my screen when working on some projects, I don't need to excuse myself to the bathroom if I need to adjust my belt, and I can stretch out after sitting for too long without feeling self-conscious), but retain much of the general air or atmosphere of a more open work environment.