One other thing you might not know is that you can save multiple 

positions in a single session (i.e. you don't have to save a session 

for each position).  Positions are named/saved with the command 

"savepos" and reapplied with "reset":

http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/savepos.html

http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/reset.html

These positions definitely include the global clipping plane positions. 

  I'm not sure about the per-model clipping plane positions.