This guide is a compact description of how to build an embedded Guitarix system. Specifically this description is for the pcDuino platform. Some detailed Linux knowledge needed, if you never compiled a kernel this might be a bit too advanced. (Eventually I might supply a filesystem image, but at the moment there is too much work in progress).
The goal is to have a box containing a virtual guitar amp which can be used on stage. The guitar is be connected to the input and the PA/monitor to the output. The box is controlled either by a floorboard with MIDI output (Guitarix MIDI control with e.g. FCB1010) or a single foot switch. The foot switch places Guitarix in a mode where things like switching to another setting or activating the tuner can be done by picking on a guitar string. Switching to a different setting can be done in under half a second with some practicing.
A smartphone or tablet (connected by wlan) can be used to display the current setting, the tuner, or even change settings or define new ones (note: remote changing/defining of settings not yet implemented in Guitarix).
The project page can be found at: http://sourceforge.net/apps/mediawiki/guitarix/index.php?title=Guitarix_Embedded_/_ARM_SoC