When we built the mechaduino as a group build at VHS, I learned a lot about the world of DIY servo control. Is that what you mean?
For just driving regular DC motors, I really like the vnh5019 (which I bought from Marginally Clever Robots!) because it provides smooth speed control and current-sense feedback. My first bottler uses this to move the carriage up and down, and uses the current-sense feedback for software-adjustable force applied to seal the bottles/cans while filling. A local brewery is still using this machine 3-4 times per week and has been for years.
Dan: what are your favourite tutorials, previous projects, etc.?