A quick interface to the Google Voice using an undocumented API

gvoice.rb

require 'rest_client'

class GVoice < Struct.new :e, :p
  def initialize(*args, &block)
    super; instance_eval &block if block_given?
  end
  
  def send_sms(number, text)
    post 'sms/send', :phoneNumber => number, :text => text, :_rnr_se => get[/'_rnr_se': '([^']+)'/, 1]
  end
  
  def method_missing(s, *a) super unless RestClient.respond_to? s
    RestClient.send(s, "https://www.google.com/voice/%s?auth=%s" % [a.first,
      @auth ||= RestClient.post('https://www.google.com/accounts/ClientLogin',
        {:service => 'grandcentral', :Email => e, :Passwd => p})[/Auth=([^\n]+)/,1]], *a[1..-1])
  end
end

GVoice.new("your@email.com", "password") do
  send_sms 5555551234, Time.now
  puts get 'inbox/recent/sms'
end