You can browse all the published concept maps without signing in. If you'd like to create your own concept maps, all you have to do is
sign in with Twitter.
The perspective that encompasses your whole life and why you're on the planet.
The reason you're here. You'll have to figure that one out. Or not. Maybe just watch TV.
The perspective that encompasses your 5 year vision.
GTD is a "bottom up" approach that focuses on mastering the mundane. Once that is done, though, there are higher perspectives that can really make the system bring about great results.
The practice of setting aside dedicated time (typically a couple of hours) to make sure your system is clean, current and complete. David Allen regularly cites this as the critical success factor for GTD.