westfw

Sigh. Here's approximately what I did:
1) Add "pins" for the various nets that went nowhere (input, output, power?) 2) renumber the Rs and Cs to (roughly) identify which part of the circuit they go with, so it's easier to see on the PCB.
3) create the PCB, put the pots on there to indicate a rough size, move the components onto the board in groups similar to those derive in (2), in ways that sort-of minimized the length of the ratsnest lines.
4) Draw a gnd (PE in your case) net around the outside, and orient all the components that connect to GND on one side so that that side would be near the outside of the board.  Connect those grounds, sort of radially.  See if there's some obvious manual routing.
5) good time to SAVE.
6) run the autorouter in single-layer mode.  See which signals seem especially convoluted, and see if it looks like it would get better if those were moved somewhere else on the board, or re-oriented.  Undo the routing and actually do the moves (hey, you can UNDO autorouting in 6.0!  Cool!)
7) Repeat (6) until things look pretty good.
8) Make minor movements that look like they'll make things "prettier."
9) Add gnd polygon.
that's probably about as much as I'll do without knowing how real the component sizes are (whether the Pots are actually mounted on the pcb, etc), or what the other limitations are, or etc.  I suspect that the circuit could fit on a (cheap) 50mm*50mm PCB without too much trouble.
(can I not add zip attachments to my own orangeBoard?  Hmmph!)
https://docs.google.com/open?id=0B6dMB5dovDUZNjk2Y2E4NzUtNjdlMy00MjMxLWIxZmItY2JhNmU3YTM4NGU3

To get rid of the labels, go to the "layers" button (just below the "i" info button), and deselect the silkscreen layers (tPlace, tNames, tDocu)

It'll take at least a bit. I'm not running 6.0 yet.

> Can I please ask you a question about the Arduino? Yes. ??

Yes, you can move the CPU from an full-sized arduino into a smaller board. (subject of an upcoming instructable, probably.) You generally need a few extra components (like the crystal.) Your best bet as a beginner would be to buy one of the reduced-sized arduino-compatibles, like the Modern Device Company "Really Bare Bones Board"

The arduino environment designates some of the pins as "analog" for connecting to sensors, and some as "digital" like turning on a motor. You probably need some sort of motor driver (chip, transistor, or relay) as well. There should be lots of info on the arduino site:
Light Sensors
Motor Control (most of these examples are probably more complex than you need.)

Well, the normal ("DIP") Arduino package is about 3.6cm long without any additional components, so you have a bit of a problem. There are smaller AVR chips, but not directly compatible with the Arduino environment, and thus harder to use. You could look at the PICAXE, which has a small version...

A standard arduino does fit inside an Altoids tin, but there isn't much more room for anything else (batteries, motors, drivers, etc) in there...)

You'll need a couple extra components - typical a resistor to keep the cpu un-reset, a "bypass capacitor", and a crystal or resonator to supply the 16MHz clock.
There are many programmable chips smaller than the one used in an Arduino, but very few that aren't an order of magnitude harder to use. You might want to look into The smaller Basic Stamp or a an 8-pin PICAxe

See also How to choose a microcontroller

woot! Finally put one of the prototypes together, and it works!

oops. Here's the picture!

We (I) did four different "Freeduino" layouts, one in 0603 SMT, one in 0805 SMT, one in 1206 SMT, and one that used as many through-hole components as possible. (xxyy SMT means that the resistors and caps are .0xx inch by .0yy inch in size. The official Arduinos are in 0805, as are the Solarbotics Arduinos.)
The board that finally made it to market (a later version than the one pictured) ended up being the through-hole version (in kit form), with just the USB chip and fuse in SMT (and pre-soldered, in the kits.) We even reverted to the big 7805-style regulator (mostly out of concerns about power dissipation when used at input voltages higher than the nominal 9V.)

Reports from the "alpha" team were that the SMT versions weren't so awful to assemble; the extra care needed to deal with the tiny components ended up consuming less time than the constant board-flipping people were used to with TH components. The USB chip is a bit nerve wracking, though!

Well, the schematic and PCB files are online at http://www.freeduino.org/freeduino_open_designs.html
I don't know that I can do much more than that. The NKC instructions for the final version should be helpful as well, though some of the parts are different.
Beware that the freeduinos (or most of them) use a different regulator than the "real" arduino, with a different pinout...

It's not too bad. Only that one SSOP chip; it was my first time soldering those, and it went "so-so."

yeah; I've put together a box of goodies. Can't mail on sunday, though!