Attempting to install rvm and ruby 1.9.2
I already installed homebrew and git, but couldn\'t get complete updates because I kept getting permission errors. Re-install
How did you install Homebrew? Their official installation instructions include running a ruby script. That should take care of the permission issues for you.
If you don't want to run a script, there is a section of that page called "Installing to /usr/local for Developers" that explains the change in permissions needed for the /usr/local directory.