libxml can be quite a PITAPITCT - Pain In The Carpal Tunnel :)

#!/usr/bin/perl --
use strict; use warnings;
use XML::LibXML;

my $doc = XML::LibXML->new()->parse_string(
    q{<?xml version='1.0' ?>
<roshambo xmlns="http://example.com/roshambo">
<sham>
<bo name="40" />
<bo name="2" />
</sham>
<sham>
<bo name="forty" />
<bo name="two" />
</sham>
</roshambo>
}
);

for my $node ( $doc->F( '//x:sham' ) ) {
    print "@{[ $node->nodePath ]}\n";
    for my $name ( $node->F( 'x:bo/@name' ) ) {
        print "@{[ $name->nodePath ]}   @{[$name->nodeValue]}\n";
    }
    print "\n\n";
}

$::xpc->registerNs( 'y', 'http://example.com/roshambo' );
print $doc->F('y:roshambo');
exit( 0 );

BEGIN {
    $::xpc = XML::LibXML::XPathContext->new( );
    $::xpc->registerNs( 'x', 'http://example.com/roshambo' );
    
    sub XML::LibXML::Node::F {
        my( $self, $xpath, $context ) = @_;
        $::xpc->findnodes( $xpath, $context || $self );
    }
}
__END__
[download]

Also if you're interested in a fancier nodePath, see XPATH DOM traverse html/xml