Google Maps Static map helper for Ruby on Rails

static_map_helper.rb

module StaticMapHelper

  def static_map_for(location, options = {})
    params = {
      :center => [location.lat, location.lng].join(","),
      :zoom => 15,
      :size => "300x300",
      :markers => [location.lat, location.lng].join(","),
      :sensor => true
      }.merge(options)

    query_string =  params.map{|k,v| "#{k}=#{v}"}.join("&")
    image_tag "http://maps.googleapis.com/maps/api/staticmap?#{query_string}", :alt => location.name
  end

end

Hey im looking for using something like this but adding a polygon in the map generated, is it possible ?