Something for people who use PHP for Mac OS stuff - a class wrapper for Theo Hultberg's nice PLIST parsing implementation. Usage example:

include "plist.php";
$plist = new PropertyList("/Users/filipp/Music/iTunes/iTunes Music Library.xml");
$array = $plist->toArray();
echo count($array['Tracks']);
6670

Great for building reports from System Profiler dumps and all sorts of cool stuff. Download here.