[James:]
> If it seems worthwhile, I can generate the ri files for 1.8.1 and host
> them on ruby-doc.org.

To me, that's a good idea anyway, as any clutter from the output can be
removed (e.g. ExceptionForMatrix).

A simple program can be written that:
 - defines the input files for 'rdoc'
 - decides which files actually need to be generated, based on
   input and output timestamps
 - run 'rdoc'
 - post-process the output to remove the aforementioned "clutter"
 - generates a tarball of the 'ri' data
 - uploads it to ruby-doc.org

Sounds like a job for Rake.  I actually implemented most of the above for
"rjay" at some stage.

Gavin