I did find several suggestions in the vtk mailing list archive. Looks like the easiest would be to create a small
render area (viewport?) in the lower left corner of the display and tie the cameras together
(how do you tie two cameras together?)

Thanks.

    -- krs 

-- 
K.R.Subramanian                           Phone: (704) 547-4872
Department of Computer Science            FAX:   (704) 547-3516
UNC Charlotte                             Email: krs@cs.uncc.edu
9201 Univ. City Blvd.                     WWW: http://www.cs.uncc.edu/~krs
Charlotte, NC 28223-0001