If you set up the symlinks to make ruby 1.8 the system
ruby, don't forget to remove the following files:

 rm /usr/local/bin/ruby
 rm /usr/local/bin/erb
 rm /usr/local/bin/irb
 rm /usr/local/bin/rdoc
 rm /usr/local/bin/ri
 rm /usr/local/bin/testrb
