This topic has come up before, and others have expressed interest in making the connection. Here's one I found: https://stat.ethz.ch/pipermail/r-devel/2003-July/027039.html You might want to contact them to see if they made any progress.
With Tom Short (the author of Rpad), we have started exploring the possibilities to use sockets by means of Tcl. Tcl (tcltk R package) is now widely usable with R, and it is possible to write a very powerful socket server with this language. You will find a first implementation of it in svSocket package (part of the SciViews bundle), and also a more advanced one to exchange HTML data in Rpad. I think this is a promising approach because it matches all items in the wishlist: it works the same on all platforms; it permits hot plug no mather the way R was started (console, Rgui under Windows, Emacs-ESS, ...), etc.
I agree with Philippe--the Tcl socket interface is a good way to communicate between OOo and R. It works well, and you can use the command line at the same time as you use the OOo user interface. Just from some quick googling, it appears that OOo has support for using sockets for interprocess communication. Hopefully, you can access this with OOo's scripting language. If you create a workbook-style interface with writer, then we might even be able to "export" the file to an Rpad application that could be hosted on a server. Also, an OOo workbook could be signifantly more powerful than an Rpad workbook. You could directly insert postscript graphics (Rpad is limited to PNG and other web-compatible graphics), and of course, the editing is more powerful in OOo. As Rpad and Sciviews do, your could probably use Eric Lecoutre's R2HTML package to have R generate formatted output that can be "pasted' into OOo writer or calc. This is effective for generating formatted reports and for notebook-style interfaces. Tom Short http://www.Rpad.org/Rpad -- Interactive, web-based engineering solutions.