nero120 said:.......... Notice how he locks his wrist and picks using his arm - that's the secret to fast and accurate picking kids!
That's just his personal preference. Players like Yngwie Malmsteen and Michael Angelo rest their pinky or pinky and ring fingers on the body of the guitar, and pick using the wrist. Others, such as Paul Gilbert and Al Di Meola use a floating hand resting on the bridge slightly. Again, they pick with the wrist.
Here's something I heard that does ring true about picking technique.
Pick one string, as fast as you can, until you can't physically go any faster. Then look at that picking motion (what ever it may be), and slow it right down so that you use the same motion to play at all speeds.
Once you've done that, you're no longer limited by your picking hand, and you just have to get practicing to get your hands synchronised and your string crossing smooth at all speeds.