I took a busted old tube screamer and rehoused it in this cigar box. I added a few pots and a photo-theremin. Now it produces a variety of distortin', ring modulatin', filterin', tone-oscillatin', and sound crunchin'. It also acts as a rich, squealing stand alone synth box.
Here it is running over an SK-1:
http://www.youtube.com/watch?v=BdrwVisg7ME
And here it is emitting sound on its own (with some Fab Echo D-Lay and a little SK-1 background):
http://www.youtube.com/watch?v=ZPGwKcd9_Ww
Sounds great!