Trevor Rabin of YES used some crazy ass thing on the Big Generator tour
it moved around like the controls on a troling motor. it looked like a wah with wah motion but also had left/right motion. he was panning sound all over the place. only concert where i felt like i was penetrated by sound. he would lay a chord down in the rear left of the stadium and rip it across to the front right, then slam it back to the left side and shoot it back to the rear again. really great musician, to bad hes so hard to get along with. guess thats why most of his work is solo