http://graph.facebook.com/http://tiddlywiki.com/
returns:
{
   "id": "http://tiddlywiki.com/",
   "shares": 395
}

bt.com has been shared 643 times for comparison. And twitter.com has been shared 1,850,692 times.
bag
jermolene_public
created
Sun, 20 Mar 2011 22:44:10 GMT
creator
jermolene
modified
Sun, 20 Mar 2011 22:44:57 GMT
modifier
jermolene