I stumbled across this trick screwing around making feedback with my
band. First, you need heavy distortion, a phaser set at a very high
rate, and a digital delay pedal, or sampler(some kind of pedal that
has a repeat on it.) Nexr, turn all your gear all the way up, and
stand as close to your amp as possible. By moving your guitar around,
over, against your amp, constantly changing it's position. This
combination makes your guitar sound like the second coming of those
litte green guys from "Mars Attacks!" Enjoy!!