lib/geos/point.rb
def to_kml(*args)
      xml, options = Geos::Helper.xml_options(*args)
      xml.Point(:id => options[:id]) do
        xml.extrude(options[:extrude]) if options[:extrude]
        xml.altitudeMode(Geos::Helper.camelize(options[:altitude_mode])) if options[:altitude_mode]
        xml.coordinates(self.to_a.join(','))
      end
    end
def to_kml(*args)
      xml, options = Geos::Helper.xml_options(*args)
      xml.Point(:id => options[:id]) do
        xml.extrude(options[:extrude]) if options[:extrude]
        xml.altitudeMode(Geos::Helper.camelize(options[:altitude_mode])) if options[:altitude_mode]
        xml.coordinates(self.to_a.join(','))
      end
    end
Build some XmlMarkup for KML. You can set KML options for extrude and
 altitudeMode. Use Rails/Ruby-style code and it will be converted
 appropriately, i.e. :altitude_mode, not :altitudeMode.