I recently had to draw up a plan for a deck that was already built. It was a bit of a pain, I had to go measure everything and eventually used OmniGraffle to put the thing together. Some people call this "existing conditions documentation", and it can be very important for something like an oil refinery where what is in place is not on paper (or is just incorrect) and new plans are being made. Some companies sell expensive services for this sort of situation where they come in with laser scanners and will build a 3D model accurate to 1/4 inch of your site.
Software and algorithms that can generate 3D models from just images first appeared aroung 1994; they're still not ready for prime time but this is definitely where situations like this are headed. It would have been great if I could have just walked out to my deck, turned on the video camera, walked around, plugged the camera into my computer and let it build up a 3D model for me in an easy to use 3D modeler liek SketchUp (or even GollyGee Blocks).
There's definitely efforts to make this happen. Microsoft's been getting a lot of press for their PhotoSynth effort. In the film industry there are programs like boujou which will take a video stream and compute the camera properties and positions, which lets animators more easily insert 3D graphics into the scene. PhotoSynth is still in the lab and probably requires a data center, and boujou is about $10K, so we're still a ways off from solving my deck program.
In 1995, on a talk about the first of these algorithms coming out of UNC, Henry Fuchs told us that he thought in 10 years we wouldn't have any more polygons, it'd be all points and images. My guess is he's only off by a factor of two -- and not only will I be able to get a 3D model of my deck from my laptop in 2015, I'll probably be able to take it down to Kinko's and have them print out a scale model with a 3D printer.