Paste this into a rails console and type "99.bottles.of_beer.on_the_wall.sing!"

bottles.rb

# paste into a rails console
# usage: 99.bottles.of_beer.on_the_wall.sing!
# alternate: 24.bottles.of_water.on_my_desk.sing!

class Bottle < ::ActiveSupport::BasicObject
  attr_accessor :value, :type, :where

  def initialize(value, type = nil, where = nil) #:nodoc:
    @value, @type, @where = value, type, where
  end

  def inspect
    t_string = type.present?  ? " of #{type}"  : ''
    w_string = where.present? ? " on #{where}" : ''
    "#{helper.pluralize(value, 'bottle')}#{t_string}#{w_string}"
  end
  alias :to_s :inspect

  def sing!
    (1..value).to_a.reverse.each do |n|
      puts ::Bottle.new(n, type, where)
      puts ::Bottle.new(n, type)
      puts "Take one down, pass it around"
      puts ::Bottle.new(n-1, type, where) unless n == 1
      puts ''
    end
    t_string = type.present?  ? " of #{type}"  : ''
    w_string = where.present? ? " on #{where}" : ''
    puts "No more bottles#{t_string}#{w_string} :-("
  end

  private

  def method_missing(method, *args, &block) #:nodoc:
    if method.to_s =~ /\Aof_(.+)/
      ::Bottle.new(@value, $1.to_s.gsub(/_/, ' '), @where)
    elsif method.to_s =~ /\Aon_(.+)/
      ::Bottle.new(@value, @type, $1.to_s.gsub(/_/, ' '))
    else
      value.send(method, *args, &block)
    end
  end
end

class Numeric
  def bottles
    ::Bottle.new(self)
  end
end