PART 2 is HERE: http://www.youtube.com/watch?v=6Otr1I0OR18
Dave shows you how to design a simple constant current and constant voltage lab power supply that can be either software (PIC/AVR et.al microcontroller) or traditional pot controlled.
Starting with the venerable LM317, and ending up with an LT3080 solution, and the some thought processes that go into it all.
Part 1 is the conceptual design of this Open Hardware design.