Build Your Own Guitar Amp Foot Switch (Under $15) - YouTube
DIY Two-Button Guitar Amplifier Footswitch
DIY: OT Pickup Machine footswitch (now with final pics!) - #84 by Markel - Octatrack - Elektronauts
LEAP#542
Footswitch Extention | Confessions of a Wanna Be Guitar Player
Amazon.com: Foot Switch 2pcs Guitar Effects Mxr Switch DIY Tap Effects Switch Footswitch Tap Tempo Effects Pedal Pedal Plastic Effector Black Guitar Tap Pedal Tempo : Musical Instruments
Dimitri De Franciscis' Blog - DIY Fender Princeton DSP 65 footswitch
Notes and Volts: Build a USB Midi Footswitch
Simple To Build Programmable Foot Switches | Hackaday