I've actually got it up and showing on my xf, the javascript portion goes inbetween the head and body elements in the PAGE_CONTAINER template.
The only problem I'm having is setting the userid into either session variable or a cookie on login with XF, looking through the code to find a good spot to do it. The script launched and added itself onto the page just fine though.
If anyone has some insite on where we can get and set the userid on login that'd help a lot.