Grapple Canceling
Grapple Canceling is a technique available for Samus and possibly other characters in Brawl. It's simple enough to pull off, and finally gives meaning to using Samus's aerial grapple. When playing as Samus, use a small jump then extend your grapple beam, it will flail out quickly doing decent enough damage/push back. It's great for halting the enemy from afar. So once you do a short jump, then use your grapple, you'll land rather quickly. Once you land, the animation for the grapple will cancel, allowing Samus to immediately move/attack.
The video below displays quite nicely the grapple canceling in action.