I wrote this a while back, before I knew about RVM. The Ruby Version Manager has a bunch of features that makes it better than macports for ruby and gem installation. Read about it here.
Getting ruby 1.9.1 and nginx and passenger and ubuntu to all play nicely is fairly straightforward, but it’s not just “apt-get” and “gem install” lovin’.
Making ruby 1.9.1 the default ruby is OK. Follow these steps: