Finally I have finished this 1 year project.
what I came up with is a lightweight greyhound that you can control with an arduino and 8 servo's

I bet there are better programmers out there that can make it walk even better and smoother.

Also included is a basic program to get you going.

http://www.youtube.com/watch?v=aDwTdbP_TBU

Updates:

14-4-2013
The Greyhound Programming stand
http://www.thingiverse.com/thing:73893

14-4-2013
Let me know If you have made a good program.
than I can put it for download on this page with YOUR name on it.

Things you need:

• 1x arduino uno
• 8x servo's (I used the cheap towerpro MG90s metal gears)
• 1x (U)BEC regulator (I used a XQ 50 Pichler)
• 1x Lipo accu (I used a 2s or a 3s)
• 17x M3X10
• 5x M3X30
• 13x M3 NUT
• Glue or you can plastic weld the pieces with the 3D printer.
• Some wires and connectors (see scamatics)
• I used a switch to cut-off the power from the servo's.

Assembly:

Download: Assembly The Greyhound.PDF

• First of all glue or plastic weld the servo horns in the right places==>
  Be aware!!! of how to mount all the servo horns on the lower legs. see Assembly The Greyhound.PDF

• Assemble the left body.

• Assemble the front and back legs of the left side.
  For the correct assembly each servo needs to be around a certain angle. for detail look in the Assembly The Greyhound.PDF

• Assemble the compleet left side.

• Assemble the right side just like the left side accept for the the following parts:
  _Neck
  _HeadSpacer
  _BodySpacer35mm
  _BodySpacer31mm

• Now that you have two halves it's easy to mount the arduino in and the rest of the cables see the picture for wiring.

Pin 1 Front Right Upperleg
Pin 2 Front Right Lowerleg
Pin 3 Front Left Upperleg
Pin 4 Front Left Lowerleg
Pin 5 Back Right Upperleg
Pin 6 Back Right Lowerleg
Pin 7 Back Left Upperleg
Pin 8 Back Left Lowerleg

• Mount it all together and your done.

to use the small programs I have written download the STAND.INO (For software calibration,this is the natural standing position.)
And the WALK4.INO (For letting it walk, also in this program you need to fill in the natural stand you figured out in the STAND program.

If you found a mistake please let me know.

I would love to see some programs and pictures of what you did.

Good luck!!!