When I was job searching in Europe, I had to produce copies of my diplomas. Never have I been asked to prove my degrees in the US, however.

My BA diploma is in a flat box along with one of my Masters diplomas and a professional certification. My other Masters diploma came in a fake leather book, which is great because it's protected. I've never framed them, but I keep meaning to. When I finish out my cottage in the backyard as my office, I'll frame them and put them there. I think I would find it odd to have them hanging in my house, but appropriate in a separate office.