Cool walking action, that is quite an accomplishment.

LOL, so it can't carry it's own battery and so has to drag it along? Good thing it's not an aircraft.

Lefty

The servos have enough torque to carry the battery. But the chassis is to small to fit my big 3S 3000mAh Lipo battery and all the electronics. I'm planning to use a slightly bigger chassis so the electronics and battery all fit inside/on top of the chassis. 

https://www.youtube.com/watch?v=3kSbl25b5KY

This is my small hexapod with 2 DOF legs, it uses an ATmega328 to control the 12 servos of the legs. Another ATmega328 handles the wireless control (nRF24L01) and controls 1 servo (to sweep the ultrasonic sensor). The first ATmega measures the current drawn from the lipo battery via an analog sensor and measures the lipo voltage through a voltage divider. The second ATmega328 controls 3 RGB leds via transistors, measures the temperature of an LM2576 voltage regulator that powers the servos. It runs a PID loop that pwms a mosfet that powers a small fan to keep the regulator cool. Can't remember to which ATmega the ultrasonic sensor is hooked up The 2 ATmegas talk to each other over hardware serial. I've used almost all the pins on both ATmegas. I now very little about programming and used the standard servo library. It uses a very simple walking gait, no fancy coding.

I'm currently working on a bigger beast with 18 standard sized metal gear servos (MG996R). The servos are controlled by an Arduino Mega 2560. I've spent the last weeks understanding inverse kinematics and managed to write a walking gait only recently. The Mega has no problems controlling 18 servos. And its calculating a lot of floating point math for the inverse kinematics. I made the following video yesterday:

I bought a PCI5-S GPS module and antenna on Ebay for less then 15$. Tried it out last week and it works I soldered some wires to the PCIe card and connected it to an ATmega328 running at 3V3/8MHz. Uploaded one of the examples of the tinygps library and after 10 minutes it gave the right position. http://www.bajdi.com/my-15-gps-module/

I have a bunch of 10W 5 and 10 ohm cement resistors for this purpose.

I bought myself a Rigol DS1053E oscilloscope a couple of months ago. Very happy with it, I use it regularly. Sometimes just as an "advanced multimeter". I also have an Open Workbench Logic Sniffer. I bought it because I am playing with several I2C sensors and IC's. It's a very handy tool to debug code.

Oops I hadn't seen the pdf file  I've just read it and cut the trace on my board. It was connected to ground just like yours. I've just uploaded the calibrate sketch and it works. Thanks for making the library and writing the pdf file. Not many libraries are that well documented 

Hi, I've tried your library but it does not seem to work with the board that I have. This is myTCS230 board (bought it on Ebay) http://www.bajdi.com/?attachment_id=940
I've connected OE to pin 8, S2 to pin 12, S3 to pin 13 and connected 5V and GND. I then tried the example calibrate sketch but I only get [0,0,0] values. The other sketches also don't work for me. The blocking sketch only gives 0 all the time, the non blocking sketch give [255,255,255] not matter what I hold in front of the sensor.

Picaxe makes a robot shield that is compatible with Arduino: http://www.picaxe.com/Hardware/Project-Boards/Instant-Robot-Shield/

I used a Dagu Red Back Spider controller (based on the Arduino Mega) in my first robot.
http://robosavvy.com/store/product_info.php/manufacturers_id/35/products_id/1574

Then I started designing my own boards with 3A switch mode regulators. I use 2S/3S Lipo batteries to power my robots. The 3A regulator drops the voltage to 5V. This way I can plug in lots of servos and sensors on my board.
My board based on the ATmega328 http://www.bajdi.com/bajduino/bajduino-3a-3/
And my latest board based on the ATmega1284: http://www.bajdi.com/something-different-a-crash-robot/bajduino-mega-3a-2/

I have 2 hexapods that use the standard Arduino servo library. One has 12 servos (2DOF legs) and uses an ATmega328P, the other has 18 (3DOF legs) servos and uses an ATmega2560. I have no problems controlling the servos with the Arduino servo library.

Take a look at the datasheet. Those 2 pins can only be used as analog inputs. The other analog pins can be used as digital pins.

You don't need to install this library if you are using Arduino 0017 or higher... It's included in the Arduino IDE and renamed to servo.h.
http://playground.arduino.cc/Code/MegaServo

The library (renamed to Servo) is distributed with Arduino releases from 0017, see the Arduino servo library reference for details. You already have this code if you are using the servo library from release 0017 or later.

How hard was it to solder the ATmega? I'm planning to make a board with an ATmega32U4. But I'm a bit worried about soldering it. I have a decent temperature controlled solder iron with some small tips, solder flux and braid. I'm just a bit worried about solder getting under the pins and connecting them.

I can recommend this company: http://www.tme.eu/en/

I have had 2 pcb's made for the ATmega1284P-PU. On both PCB's I put the crystal and caps inside the socket. Never had any problems with uploading sketches. One of the PCB's I use in a small robot. I have uploaded hundreds of sketches to it while testing. I have 4 1284P-PU chips in use at the moment all with datecode 1216.
I now very little about designing PCB's. Is putting the crystal and caps inside the socket a bad design?

Did you change the xtal to a 20MHz one?

Yes, 20MHz crystal bought from Tayda Electronics. I tried 2 just to be sure. I also tried putting the chip on a breadboard with 20MHz crystal, caps, ... but got the same error. I can upload sketches through my USBasp but can not make a serial connection.