System-wide Keyboard Shortcut for Moving to Sidebar/Next Column
Thinking outside the box:

If the only reason you want the keyboard shortcut, is to avoid your mouse, have you considered a trackpoint keyboard?

Because I had RSI in the past, trackpoint keyboards are about the only ones I can use (even at clients, I usually bring my keyboard, or work from my laptop that has such a keyboard).

The big upside of those keyboards is that you don't have to take your hand of the keyboard in order to use the mouse.
For trackpads I still need to (somehow using my thumb is far less accurate on trackpads than using my index finger, o I still need to lift my hand for pointing).

It takes a little while to get used to a trackpoint, but I can't do without them any more.
USB trackpoint keyboards work equally well on Mac and PC.

--jeroen