And Aardvarks! :
I posted one a while back on Facebook... this one's better.

You'll wanna run a 9V zenner diode from the gate to the source of the BS170. Cathode (side with the line) goes to the gate. Or you can socket the transistor and just keep an extra one around. The diode protects it from ESD damage.
-edit-
Possible mods include:
Increase R2 for more gain. It'll also interact with the tone control and make the whole thing a bit darker.
Decrease R4 (probably just by jumpering it) for more gain. This will interact with C1 and give you a brighter sound.
Use two 1N6263s instead for more distortion, but less volume.
Decrease C1 for a brighter tone. .01uF works well on guitar.
To get a mid-scooped tone control, put a small cap (like .001uF) across the tone control.
They stack really well-- so try running two together. You can leave out the switch, tone control, and volume control from the first one, too. They either don't affect much, or they're redundant.
Gnomeratron VTF:
You'll wanna view this one at 100% or print it. : )
Team Tesla:
You repeat the whole circuit for each output (except the first 100uF cap). The cap values aren't critical, and you can get away with lower values, generally. The common mode choke at the output is absolutely essential, as the chips will interact otherwise. You can replace the input one with a normal LC filter if you want. The problem is, I was only able to find suitable CMCs in SMD. You can use a standard 7809 regulator if you can't find the Toshiba part (or an equivalent). It's a 150mA version of the 78L09. The first output should be grounded to the enclosure. The rest shouldn't.
In the near future, I'm doing a more efficient version using completely different parts. I'll post up the schematic, but it'll probably mostly SMD.