Pandora GP2X-style, but we haven't seen much in the way of progress until now, with the OpenStomp Coyote-1 project. It's still in the prototype phase, but it looks well thought-out, with a Parallax Propeller 8-core processor running at 80MHz at its heart that can even generate basic video, 44kHz 24-bit sampler, two foot switches, and a two-line LCD screen for feedback. The main dev, Eric Moyer, says he wants the pedal to serve as an "audio sandbox" with totally open-source software and fully documented hardware, and we've got say we're pretty intrigued by the idea -- we'll be watching this one closely.
Read - OpenStomp home
Read - Forum thread with demo song