| Steve Vai and his mentor, Joe Satriani, created a guitar effect technique known as the Lizard Down the Throat. It can be heard on various Vai albums, and the only way to describe it's sound is; think of what it would sound like as you shove something down a lizard's throat...
Take your guitar, and screw in your whammy, or tremolo, bar. Place your the pick in your fret hand. Grab the whammy bar, and dive down as far as it goes. This means push the bar closer to the body of the guitar. Meanwhile, run the pick from the head of the guitar, down to the bridge. This should create a unique gcgcgcgcgcgcgcgccgggggcc sound...
As far as I can figure, this is basically how it's done. Aslo experiment with a wide range of drive settings. Now maybe if we were all robots like him, we might have a better chance. | 
