Some devices give access to that stuff, I believe. See the upcoming Pyra for a fully-open hardware Linux PC that's about the size of a Nintendo DS. And see Keyboard.IO for a fully-open keyboard, including source code, hardware design, etc.

Though it is a good question that raises a lot of questions of what things we're using have source in them that we can't touch that we don't normally think about. I don't think I'd ever thought about firmware in a monitor or keyboard.