For me I got a Magpul AFG, been watching their DVDs and I'm going to try using the grip that they always talk about. The grip is the same concept as rotating your support hand forward on a pistol so you can have control over the front portion of the rifle. It also comes from competition shooters that do alot of fast target transition, you have better control of front end of the rifle if you angle you grip rather than holding a vert grip which could cause alot of sway when transitioning.
AFG - Angled Fore Grip - AFG-1 - Angled Fore Grip