My current .irbrc

.irbrc

begin
  # load wirble
  require 'rubygems'
  require 'wirble'

  # start wirble (with color)
  Wirble.init
  Wirble.colorize

  # customize the colors a bit
  colors = Wirble::Colorize.colors.merge({ :string => :dark_gray })
  Wirble::Colorize.colors = colors

rescue LoadError => err
  warn "Couldn't load wirble.  That might be ok if you're using an RVM gemset.  Otherwise, gem install wirble."
end

begin
  require 'hirb'
  Hirb.enable
rescue LoadError => err
  warn "Couldn't load hirb.  That might be ok if you're using an RVM gemset.  Otherwise, gem install hirb."
end

IRB.conf[:PROMPT_MODE] = :SIMPLE

class Object
  # Return only the methods not present on basic objects
  def interesting_methods
    if self.is_a? Class
      (self.public_methods - Object.public_methods).sort
    else
      if self.is_a? Module
        (self.public_methods - Module.public_methods).sort
      else
        (self.public_methods - Object.new.public_methods).sort
      end
    end
  end
end