Christopher at Pictureline
Sample photo of the DX-sensored Sigma 30mm f/1.4 on the FX (full-frame) Nikon D700
The vignetting is actually not too bad on the FX Nikons. In some cases it might look OK (artsy, etc.) otherwise you can either set the camera to autocrop to DX or just do it yourself. You'll obviously lose resolution, ~3 MP.
Pictureline (camera store)
Salt Lake City, UT