a web interface to identify()

Maybe Barry Rowlingson's imagemap is all you need?
http://www.maths.lancs.ac.uk/Software/Imagemap/

Thank you for that suggestion.  Unfortunately the plots can involve  
hundreds of thousands of points, and our initial tests with imagemap  
indicated that for this many points it takes too long and generates  
too heavy an html document.  So we are looking for a lighter weight  
solution in order to keep the application responsive.  Current  
thought is to use fifo's between cgi scripts and a single persistent  
R process...

-jon