In python 2.5 socket.close, all methods are delegated to _dummy, which raises an error.  It would be more consistent to delegate each method to its counterpart in _closedsocket; in particular re-closing a closed socket is not intended to raise:

    def close(self):
        self._sock.close()
        self._sock = _closedsocket()
        for method in _delegate_methods:
            setattr(self, method, getattr(self._sock, method))

On trunk:

>>> import socket
>>> s=socket.socket()
>>> s.close()
>>> s.close()
>>> 

It also seems that the following line will make even that remapping not useful?  Isn't it better just to avoid the layer of indirection and directly proceed with assigning to _dummy?

line 145: send = recv = recv_into = sendto = recvfrom = recvfrom_into = _dummy

Re-closing a socket does not raise an exception.  If there is something else in your bug report that I am missing, please re-open it.