[R] Lattice plot of multiply-nested data

[Ross Darnell]

I would like to replicate Figure 3.12 from Pinheiro and Bates's "Mixed 
Effects Models in S and S-PLUS"
but I would like to plot both the average line as well as the individual 
sites lines on the same panel.
I did try modifying the panel function but I cannot seem to  get it  as  
described.

I would appreciate any suggestions

Ross Darnell
University of Queensland