I would suggest to add it to your template footer. You have to do it using admin control panel and editing your template.
Get your urchin tracking javascript code for Google Analytics. Go to: AdminCP -> Skins & Templates -> Style Manager Click the << >> button for the skin you want to edit. Now open/edit the 'footer' template from the list. Now find this code (it would be in the end of the template) : <script type="text/javascript"> <!-- // Main vBulletin Javascript Initialization vBulletin_init(); //--> </script> HTML: And add your analytics code AFTER the code snippet given above. Then [save] your template.