Or, move your killswitch to the floor
One of the great cheap guitar tricks is to make your guitar stutter. This is usually done by turning one of your volume knobs all the way off and then using the pickup selector back and forth to get a rapid on/off effect. I've received some emails from folks trying to build these, and some with a few interesting variations. There are loads of resources on the web for adding a stutter switch directly to your guitar, so I'll concentrate on building this simple device as a pedal.
Here's how stutter works: you simply connect the signal wire to ground. That effectively grounds, or turns off, the signal from your pickups. Pretty hardcore :)
A dude named Kevin wanted the reverse: a stutter switch that kills the signal until you press the button. Such an arrangement would work best if it also has a bypass switch. Otherwise you'd have to hold the momentary switch down the entire time you wanted to hear your guitar. This one is accomplished by splicing a SPST toggle switch before the momentary switch. Notice also that we use a Normally Closed momentary switch here.
This one works just like the Simple Version except it adds a potentiometer so you can adjust the amount of stutter.
Use a metal enclosure for good shielding, any Hammond type will do. As for the momentary switch, try and find a good heavy-duty switch--the crappy plastic ones from Radio Shack will last approximately 2 seconds if you stomp on them.
Smallbearelec.com sells good switches.
For the normally open momentary, try the Carling 110-PM-OFF switch:
Good luck and have fun!