R help - Feb 2011 - Bwplot with dendrogram to indicate significant differences

I would like to make a box plot with a dendogram on top that can be used 
to indicate significant differences (with an asterisk or three at a node 
depending on the p-value). I can supply the adjacency information a 
priori. Is there an easy way to do this? Other ways of presenting the 
same information would be welcome.

I am currently using lattice's bwplot, and would like to continue doing 
so as I have additional code to customize the display (displaying 
individual data points in red or black depending on whether they pass a 
predetermined threshold).

Michael