Tool for detecting "social widgets" problems on your site

People asked for a simple tester for the problem that I've described in the topic "Your social widgets are losing you visitors right now": http://news.ycombinator.com/item?id=1771607 (in brief: are there any scripts on your pages that can significantly slow down your site and therefore cost you some real visitors that won't wait 2 minutes for page to load).

If you see any "non-async scripts" on your site - you're potentially significantly slowing down your site.