Installing Tesseract on a Mac (OSX 10.8)

Despite finding several pages with instructions on how to install Tesseract, I found that I had to cobble together my own set of instructions using bits and pieces of information I gathered from all of them.
UPDATED - May, 2015: With the assistance of many fantastic participants in various OCR workshops we've held over the last year, these instructions have being updated. The following is what has worked best and most consistently for most people.