Fixed: my attempt at using a yml file to configure the twitter gem.

config.yml

:twitter:
    :consumer_key:       Buncharandomletterssee
    :consumer_secret:    BuncharandomlettersautogeneratedformebyTwit
    :oauth_token:        Thisoneh-asadashinthemiddleofittomakeitseemmoreimp
    :oauth_token_secret: IgetanilrelatederrorwhenItrytousethiscruftI

ymlconfig.rb

require "twitter"
require "yaml"
    # The fix is in, initially I was looking for an array called twitter inside an array called twitter, which returned nil. Doh!
    # See also: Configuring YAML: http://blog.innovativethought.net/2009/01/02/making-configuration-files-with-yaml-revised/
    # And setting up the Twitter gem: https://github.com/jnunemaker/twitter/blob/master/README.md

  Twitter.configure do |c|
    config = YAML.load(File.read("config.yml"))[:twitter]
    c.consumer_key       = config[:consumer_key]
    c.consumer_secret    = config[:consumer_secret]
    c.oauth_token        = config[:oauth_token]
    c.oauth_token_secret = config[:oauth_token_secret]
  end

s/APP_CONFIG[:twitter]/APP_CONFIG/g

@briantrice Initially I was confused by your comment, then I realized you were indicating replace with vi syntax. Thx for the helpful tip!