Not the most versatile sound, but a goodie, that I certainly think has some nice uses. Anyone who tries this and is skeptical about how useful such a sound is, listen to Hendrix's "1983... A Merman I Should Turn to Be" on his Electric Ladyland album. There are some sounds in the middle section that sound to me like he eitherr uses this wah technique, or he uses a slide above the pickups with his bridge pickup selected.