QUOTE (Jonathan Wienke @ Jan 11 2008, 05:54 PM)
Nope. Nikon (and many other brand) lenses can be adapted to fit Canon, but not the other way around. I forget the technical term, but it has to do with the distance between the lens mount and the plane of focus on the sensor/film. This distance is shortest on Canon, so Nikon lenses work fine on Canon with the adapter occupying the additional space needed for proper focus. But to get a Canon lens to focus on a Nikon, you'd have to chop off the rear of the lens and fabricate a new mount that would shorten the entire lens body.
The diameter of the Nikon mount is much smaller than Canon's.