Actually, 34 years ago this technique was used to support the Upper
Deck at Yankee Stadium after the columns & decorative frieze were
removed:

http://www.flickr.com/photos/wallyg/152457252/sizes/l/
Cable suspension!

That's right.

It just hit me that a home with a front porch, like:


http://www.flickr.com/photos/13083606@N02/2690725215/

or: http://www.flickr.com/photos/62765927@N00/110279946/ (notice side
profile of porch next door - this would be most feasible!)

Finally: http://www.flickr.com/photos/rnmary/2680235685/ (in this
application, ideal porch roof profile is present but carries across
garage. Cabling would obviously not be necessary at garage end.)

Could have unrestricted views from inside or on the porch with a roof
supported partially via cable tiebacks reamed through the vertical
studs inside the exterior house wall. Any railing or waist-high wall
would remain on the porch for the restraint of children or pets, but
there would be nothing contacting both rail or roof. These cables
would run just under the roof slope of the porch roof, and be tied in
a similar fashion at the front end of the overhang. They would share
the load with existing rafters gusseted into those vertical exterior
wall members.

My criteria include:
-NO residential space above the porch roof(temporary occupancy allowed
as evacuation route in fire).
-MUST be able to support the weight of a standard occupied porch swing
and/or at least 12" of snow.
-Vertical studs to which cables are tied CANNOT have any rot/cracking/
other degradation, or home would be disqualified from having a
pillarless porch roof.
-Porch depths up to EIGHT feet are feasible.

No doubt it would take most people some time getting used to seeing a
typical bungalow or two-story farmhouse with the porch roof just
"hanging" there, but I think it would really open up the view a lot.

If they could do this 35 years ago at Yankee Stadium, resulting in
cantilevers over 50' deep, then I'm sure the technique could be scaled
town to residential applications.

Viable, anyone?

-ChrisCoaster