Marcelo Giangrande makes MG pedals (and a cool little range of amps) in Sao Paolo, Brazil. His bright pink "That's Echo Folks" pedal is an analog delay controlled by a light-sensitive sensor on a tail. BugBrand
In Bristol, England, Tom Bugs makes a big range of lo-fi sound mangling devices. His Mini-Modular is a little slope-fronted box full of circuits to modify other sounds, or create them from scratch. It's also a synth, but don't expect it to play in tune. His Bug Crusher is a stompbox which uses an analog process to roughly reproduce the bit-reduced sound of old samplers and circuit-bent toys. Trogotronic
While MG gear is kitsch and colourful, Trogotronic's stuff is butch: Huge, custom-modified all-tube signal generators and effects, and the Iron Cross, a bombproof arcade joystick turned into a four-way signal router. Guyatone Optical
Guyatone pedals are a little less underground than the others featured here - they're made in Japan in a factory, rather than someone's garage - but they make up for it through over-engineered complexity and an exuberant number of lights, switches and controls. Their Ultron filter pedal even has old-school DIP switches inside for further tweaking. Schumann Electronics
In the back room of a music store in Brooklyn, John Schumann builds pedals for bands like Portishead and Radiohead. His pedals are fantastically esoteric, like the PLL: an "analog harmonizer" which plays along with the notes you're playing. Effector 13
While most pedals are aimed a guitarists, the Effector 13 Synth Mangler is designed for keyboard players. It's two channels of ultra-fuzz, controlled by a joystick and a "magic eye" light sensor.