Ben Patterson - One of the biggest online video sites in the world (not to mention a fairly big deal in the social-networking arena) is finally renting movies. First up: "The Dark Knight," Christopher Nolan's summer 2008 blockbuster. You can go ahead and …<p><strong>Read more:</strong> <a class="rssreadon" rel="external" title="Now playing on Facebook: “The Dark Knight”   (Ben Patterson)" href="http://us.rd.yahoo.com/dailynews/rss/tech/*http%3A//news.yahoo.com/s/yblog_technews/20110308/tc_yblog_technews/now-playing-on-facebook-the-dark-knight" target="_blank">http://us.rd.yahoo.com/dailynews/rss/tech/*http%3A//news.yahoo.com/s/yblog_technews/20110308/tc_yblog_technews/now-playing-on-facebook-the-dark-knight</a></p>