gistfile1.rb

# simple script to convert a Word Doc to a PDF using Google Docs

require 'rubygems'
require 'gdocs4ruby'

service = GDocs4Ruby::Service.new
service.authenticate("username", "password")

doc = GDocs4Ruby::Document.new(service)
doc.title = 'testing'
doc.local_file = 'testing.doc'
doc.save

id = doc.id.gsub('document:', '')

# workaround for bug in GDocs4Ruby::Document : 81
request = GData4Ruby::Request.new(:get, 
                                  'https://docs.google.com/feeds/download/documents/Export', 
                                  nil, 
                                  nil, 
                                  { 'docId' => id, 
                                    'exportFormat' => 'pdf' })

response = service.send_request(request)
File.open('testing.pdf', 'wb+') { |f| f.write(response.body) }