This type of functionality usually comes at a price, and in this case the price was having to use a mouse.

There are a number of keyboard shortcuts, but the it is a full page help buried in the preferences pane.  I prefer the narrow right-hand window like the type seen in some Microsoft office products.

So I copied the docs and make a little bookmarklet for myself.  Feel free to use it.

Smartzone Keyboard Shortcuts

To use this as a bookmarklet, just drag it over to your bookmark or favorites bar!