You can always test things on a local CVS server too. You can just
that's probably a good idea ...
copy the CVS files to your machine, and set your CVSROOT to point to them, then try anything. SourceForge used to provide a way to directly download the CVS files, but I haven't tried recently.
that seems to be a useful feature (although i won't download the files with my poor dialup connection) anyway ... do you know if there is any cool cvs feature that allows one to mirror (and sync) a local cvs server with the sf cvs?
cheers ... tim