A very nifty trick that a lot of the great Guitar Gods use when playing outside. I actually learned this trick from a piano player that I used to jam with at school. I first noticed him playing some seriously outside lines and when I asked him he just told me that he was playing 4ths in a chromatic fashion.
Later on I kept exploring and kept seeing similar patterns in different solos and licks. Eventually, I decided to start creating my very own patterns using this trick.