Jabra, author of Nikto's XML output format, has just released Nikto::Parser (along with several other security tool parsers). This perl module takes in a Nikto XML file (or runs Nikto directly) and creates an easily accessible interface to the data.

Here's an example reading in a saved scan file.

 my $npx = new Nikto::Parser;
 my $parser = $npx->parse_file("nikto.xml");

 foreach my $h ( $parser->get_all_hosts() ) {
     print "ip: " . $h->ip . "\n";
     foreach my $p ( $h->get_all_ports() ) {
         print "port: " . $p->port . "\n";
         print "banner: " . $p->banner . "\n";
         foreach my $i ( $p->get_all_items ) {
             print "Description:\n" . $i->description . "\n";
         }
     }   
     print "---\n";
 }

Nikto::Parser on CPAN
Nikto::Parser on spl0it.org