## untested code
   use strict;
   use XML::LibXML;
   my $parser = XML::LibXML->new();

   my $doc = $parser->parse_file( 'http://www.perlmonks.org/index.pl?node_id=30175' );

   ## find all "Discussion" section
   foreach my $disc_node ( $doc->findnodes( '/NEWESTNODES/NODE[ @nodetype="monkdiscuss" ]' ) ) {
      ## do something with it...
   }