I shoot panos with a Nikon D200 and Nikon 10.5 mm, 18-200mm and 35-105
with a Kirk Ball head, Really Right Stuff PCL-1 Panning Clamp and their
MPR -192 rail. I've identified the nodal point for these lenses at
several focal lengths and written them down on card stock that I've cut
to fit into the rail and hold with a little glue.
The bubble level on the Panning Clamp lets me quickly level the ball
head/clamp and the scale on the rail lets me set the nodal point in a
few seconds. Pano have enver been so easy.