Create a 2d index.  See:
            http://www.mongodb.org/display/DOCS/Geospatial+Indexing

            :param name: Name of the indexed column
            :param min: minimum value for the index
            :param max: minimum value for the index

def geo2d(self, name, min=None, max=None):
        """ Create a 2d index.  See:
            http://www.mongodb.org/display/DOCS/Geospatial+Indexing

            :param name: Name of the indexed column
            :param min: minimum value for the index
            :param max: minimum value for the index
        """
        self.components.append((name, GEO2D))
        self.__min = min
        self.__max = max
        return self