The Biscuit Box: A three channel amp/mixer for portable devices.
3 channels in (all Mono)
2 channels out (one mono, one psuedo stereo)
Speaker that can be turned on/off
Master Volume plus Vols for each input.
Yeah, it's not exactly high tech. Nor is it terribly well built. But I'm a rank novice with electronics and this is by far the most complicated thing I've built. The amplifier is the guts of an off the shelf RadioShack mono amp. It's not really great sounding but I'm just playing for fun.