So, I haven't tried this yet, but I plan to and if it works it will be pretty cool... (if it doesn't, I guess I'll have to start it as a suggestion on the Idea thing).
JHS makes a pedal that they call the stutter (or something like that) and it is a momentary killswitch. Basically, you can tap the switch on this pedal and it kills the signal until you let go, so you can tap a patter and it will "stutter" to that pattern. I was thinking that I might be able to set up a footswitch on the HX effects to do the same effect (have it control the position value of the volume pedal effect with the level 100 normally and have it go to 0 when depressed). What ya think?