Ah ha Hal,
The Electric Hinge! Only heard about them, never seen one used. http://www.nokey.com/electrichinge.html
And the armored cable loop: (The cheapest method.) http://store.yahoo.com/853111/allocardoorc.html
Had a job where somebody attmpted a break-in by slipping a wire in and yanking the door cord until it severed. It did nothing but have me out there re-doing the thing all day.
The one from my first post comes in a 2-wire, and 10-wire. Very hip for access card readers or other devices. It is also the coolest one I have done to date in a wood door. No visible cord, or mis-match on hinges. The one I did was a non-rated Residential front door. It was custom made and I had the guy making it route a path in it. From what I remember was about $150, and had to call to find distributor, etc.
As for getting the wire there. Like Hal said, A steel door is easy. Wood door - make a carpenter do it! But if forced to: Stand the door on end. (hinge up strike down and plumb) Take a 48"X3/8" drill bit rigid, not flexible, and aim for the mortise! Here's the key! Stand a lazer level on the hinge side as a guide to remain centered in the door to reduce drift. DO NOT force the drill, the bit will flex! 3" pull out and clean, and repeat.
Wish you luck..............