>gem install rails
command. I kept getting an exception like this:
ERROR: http://gems.rubyforge.org/ does not appear to be a repository
Well, I kept messing with gems.rubyforge.org, when it appear that the gems install on the mac was actually the problem. So I tried gem udpate --system, which, of course, failed because it tries to talk to gems.rubyforge.org.
Solution...go to http://rubygems.org/pages/download and manually download an updated gems..once I did this, gems, now properly configured with the gem repository, seems to work fine.
Back to Rails and Ruby after something of hiatus, delayed for several hours messing with gems. Tolerating frustration is a vital part of the developer's tool-set.