Set the latest tweet from @Cmdr_Hadfield as desktop background

hadfield.rb

require 'json'
require 'open-uri'

TIMELINE_URL = 'http://api.twitter.com/1/statuses/user_timeline.json?screen_name=Cmdr_Hadfield&include_entities=true&trim_user=true&exclude_replies=true'

class Tweet < Struct.new(:tweet)
  def media
    tweet['entities']['media'][0]
  end
  def image_url
    media["media_url"] + ':orig'
  end
  def text
    tweet['text'].gsub(media['url'], '').strip
  end
  def write_image filename
    system %(convert '#{esc image_url}' -fill white  -undercolor '#00000080' -gravity South -annotate +0+5 '#{esc text}' '#{esc filename}')
  end
  private
  def esc text
    text.gsub("'", "''")
  end
end

json = open(TIMELINE_URL).read
data = JSON.parse(json)
tweet = data.detect{|x| x['entities'] && x['entities']['media'] }
tweet = Tweet.new(tweet)
tweet.write_image '/tmp/bg.jpg'
system 'feh --bg-scale /tmp/bg.jpg'

preview.jpg