> By far the most common way is chain of command, which means that you always flow communication through your manager. The problem with this approach is that, while it serves to enhance the power of the manager, it fails to serve the company.

Is this common at a lot of companies? I've only worked in one company and despite its many flaws I've never hesitated to contact the relevant person directly for anything, regardless of hierarchy and geography. I do make sure to keep my manager in the loop for anything that will take up a significant portion of my time. So he knows I'm not slacking off :P