Please forgive me for lowering the intellectual tone (as usual) and going for simplicity. I once saw on a heavy rock instruction video for 5-year-olds (at least, that where it seemed to be pitched) that wonderful simple one-chord-fits-all shape that the guys have described, thus:
3rd fret, low E string and 5th fret A string, G and D, is your G chord. Move the whole shape up two frets, and it's your A chord.
Use the same pattern on the next two strings up, A and D, and you get a C chord, moving up two frets to a D, and then going up again to wherever you like.
I promise you, this video showed kids how to put their guitar on to full screech and play Hey Joe without moving that pattern of left hand fingering at all, just moving the entire arm and wrist!
I was delighted to discover that with a bit of thought and considerably more delicacy, you can actually do a hell of a lot more with that one shape.
But I'll never use it for Hey Joe...
- Ian B