I have long been a fan of the various tutorials written by Dan Benjamin at Hivelogic for installing the various components of a Ruby on Rails development environment. Some of these articles are:

• Installing MySQL on Snow Leopard
• Installing Git on Snow Leopard
• Installing Ruby, RubyGems, and Rails on Snow Leopard

Recently, however, I have found a new way to install Ruby, RubyGems and Rails. This new method allows for a simple installation and switching between different versions of Ruby. Enter, Ruby Version Manager (aka RVM). Once installed and configured, installing Ruby is as simple as:

rvm install 1.9.1

I was introduced to this magical tool via a screencast from Ryan Bates on Railscasts entitled: Rails 3 Beta and RVM