Simple Google Geocoding API V3 client. All I needed was a state name given a postal code. Might be interesting to build this out, but felt I'd share the basics first.

geocoding-google.rb

require 'uri'
require 'multi_json'
require 'net/http'

# Simple client wrapper around Google Geocoding API V3
# https://developers.google.com/maps/documentation/geocoding
#
#    geo = Geocoding::Google.geocode('91106')
#    geo.state
#
module Geocoding
  module Google
    API_URI = URI("https://maps.googleapis.com/maps/api/geocode/json")

    def geocode(address)
      req = Request.new(address)
      req.run
    end
    module_function :geocode

    class Request
      def initialize(address)
        @address = address
      end

      def uri
        uri       = Geocoding::Google::API_URI.clone
        uri.query = URI.encode_www_form(:address => @address, :sensor => false)
        uri
      end

      def run
        get = Net::HTTP::Get.new([uri.path, uri.query].join('?'))
        req = Net::HTTP.new(uri.host, uri.port)
        req.use_ssl = true

        res = req.start { |http| http.request(get) }

        case res
        when Net::HTTPSuccess
          json = MultiJson.decode(res.body)
          Result.new(json)
        else
          nil
        end
      end
    end

    class Result
      def initialize(attrs)
        @attrs = attrs
      end

      def state
        return nil unless ok?

        components = results.fetch('address_components')
        c = components.detect { |ac|
          ac['types'].include?("administrative_area_level_1")
        }
        c['short_name']
      rescue
        nil
      end

      def ok?
        status == 'OK'
      end

      def status
        @status ||= @attrs['status']
      end

      def results
        @results ||= @attrs.fetch('results').first
      end
    end
  end
end

test-geocoding-google_test.rb

require 'test_helper'

class Geocoding::GoogleTest < Test::Unit::TestCase
  def test_url
    req = Geocoding::Google::Request.new('91106')
    uri = URI("https://maps.googleapis.com/maps/api/geocode/json?address=91106&sensor=false")
    assert_equal uri, req.uri
  end

  def test_state
    geo = Geocoding::Google.geocode('91106')
    assert_equal 'CA', geo.state
  end

  def test_status
    res = Geocoding::Google::Result.new("results" => [], "status" => "REQUEST_DENIED")
    refute res.ok?
    assert_equal 'REQUEST_DENIED', res.status
  end
end

Any plans to build this out? If so, I will contribute.

I might do a bit more with it, but I don't think I'll ever build it into a full scale geocoding suite that the bigger gems do.