package MyHTTP; 
use base qw(LWP::Protocol::http); 

sub _extra_sock_opts {
   my ($self, $host, $post) = @_
   my @opts = $self->SUPER::_extra_sock_opts($host, $post);

   push @opts, LocalAddr => $ENV{LWP_LOCAL_ADDR}
      if exists $ENV{LWP_LOCAL_ADDR};

   return @opts;
}

LWP::Protocol::implementor( 'http', 'MyHTTP' );

1;

##</code><code>##

push @LWP::Protocol::http::EXTRA_SOCK_OPTS,
     LocalAddr => $ENV{LWP_LOCAL_ADDR}
   if exists $ENV{LWP_LOCAL_ADDR};