Dan(dpm) a while back did an epic post about a tight control for guitar. Well here's Joe Gore using a similar concept but with a standard tone knob as well and you get to see all of his epic guitar faces as well.
[VIDEO]http://www.youtube.com/watch?v=yVC-Fj9Lz-s]2-Band Tone Control.mov - YouTube[/VIDEO]
Two-Band “PTB” Tone Control: Useful, Easy, Cheap & AWESOME! | Tone Fiend