Source Audio just provided me with a new Distortion pedal.
The Soundblox Pro Multiwave Bass Distortion. This thing is amazing. It can store 6 presets (including EQ) and has many different types of distortion.
It'll allow you to choose the frequencies to get effected as well as give you distortion up an octave. (I have no idea how it does that.) You can also use an expression pedal to fade between presets.
It's way cool.