The Novation Remote Zero gives you a bunch of sliders and knobs that you can use to alter the image that LivePro projects. You can link those controls to just about any feature in the software. So instead of using the controls on the screen, you use the Remote Zero.
One of the coolest effects (in my opinion) is to alter the scan-rate with one of the vertical sliders. This changes the display from a bunch of smooth lines to a collection of staccato beams. Also, the sliders are great for fading effects in and out at will.
The knobs are useful for rotation effects. You can use them for absolute rotation (shift something 45 degrees, then shift it back), or for continuous rotation (in which case you adjust the speed). It takes some time to get adept at adjusting this on-the-fly while the music is playing, but you can do some very cool things with just a few controls.
You can also use the push-buttons for all kinds of things, including pop-in cues, page changes, cue selection, effect selection, black-out, tap-sync, rotation/position reset, and so on.
I've only scratched the surface of what is possible with a controller like this, and truthfully I'm not very good with LivePro yet, but I am learning. You need to spend a lot of time just playing with it to get a feel for how you use it to create a show. (Sort of like learning how to play an instrument...)
Adam