One of Siri's more convenient features has always been its integration with Yelp, the business-rating social website. When Siri first showed up in October, a query about finding restaurants or other nearby businesses would give you a response showing a listing by either Yelp ranking or distance. However, tapping a listing wouldn't take you to Yelp to check out comments by others about the business. Now the Yelp Official Blog reports that iOS 5.1 adds even more powerful in