Using this site you can create very high resolution maps sourced from Google Earth http://www.nearby.org.uk/google/nolabels-map.php.
This is the highest zoom:
By stitching together these images, flat or at an angle, a high resolution map can be created. I experimented with image effects to create a site plan of sorts. Though rather crude, its a good start. The map images below document Brownfield sites (red), empty buildings (yellow) and the enterprise island (green).
The image below is over 3000px across.