When Jon Martin found an old Kodak Ektar 101mm f4.5 lens from the 1940′s at work, he decided to try it on his D700 by freelensing to testing and see if it was compatible. After finding that it was, he began on building a rig to use it as a tilt-shift lens. He ended up building a rig using old camera gear and some custom wood parts.
Here are some tilt-shift shots he took using the rig:
You can read a much more detailed account of how the rig was constructed over on Martin’s website here.