gistfile1.rb

#!/usr/bin/env ruby
require 'rubygems'
require 'active_support'

class John
end

j_c = John.class_eval do
  def hi
    'hi'
  end
    
  class << self
    def friendly_param(parameter_name)
      cattr_accessor :friendly_param
      self.friendly_param = parameter_name.to_s
    end
  end
  self
end

j_i = John.instance_eval do
  def hi
    'yo'
  end
    
  class << self
    def friendly_param(parameter_name)
      cattr_accessor :friendly_param
      self.friendly_param = parameter_name.to_s
    end
  end
  self
end

puts j_c == j_i           #=> true

John.friendly_param :beans
puts John.friendly_param  #=> beans
puts John.new.hi          #=> hi

puts John.friendly_param  #=> beans
puts John.hi              #=> yo