Just finished up a 4 layer printed circuit board I have been working on.  This board has split analog/digital gnd and power planes (1.8V and 3.3V). Below are two photos, where the left is a photo-mode printout of the top (component) layer and the right is a screenshot of the program I used to build it (PCB of the gEDA project).  Here are the photos in larger resolution —>  HERE1   HERE2

This board will allow me to control a 0-400 MHz Analog Devices DDS chip from my host computer via the FT2232HQ Mini Module which interfaces to my board via female headers.  Just to give you an idea of why I would do something like this, other arbitrary waveform generators (AWG) from companies like HP or Agilent are very expensive (but very nice as well).  For something up to 400 MHz you could even be looking up into the $20,000 range.  This board, once its all done will cost approximately $150. 

All the parts have been ordered except the for the Analog Devices chip which is on backorder till December!!!  In the mean time I got the PCB fabbed using BatchPCB (see slideshow).  I have virtually finished up coding the GUI that will control everything from the host.  Here is a a look at one of the many tabbed windows.