Usage jQuery $.getJSON is not available now, because of security conflict.
So you can't add simple BTC price ticker to your website or application without server script.
Header should be:
'Access-Control-Allow-Origin: *'
After this error I've tried next JSONP (quirk):
MIME type of response is 'text/html'
It is easy to fix it. I've wrote them on twitter (http://twitter.com/vvmspace), so I hope that it will be fixed.