Hi,
while sitting on the entire R stuff I had an idea concerning Rmate.
If Rmate plots something it will save these images (PDFs) in a temporary folder, and at the end it will open these files in Preview. Fine. My suggestion is, instead of open Preview automatically to display all images inside of the Rmate output window as pdfs right after the last output. If one clicks on an image it opens it with the default application, or one can drag it to a location to save it as pdf.
As demo I did a screencast 9MB http://www.bibiko.de/TMRmate.mov
Would this be useful?
Best,
--Hans