I was surprised at first when I read this, but given the proliferation of Smartphones, it's actually not that hard to believe. Even my 64 year old father uses a Blackberry and my 10 year old nephew has an Iphone. Yelp has become the trusted go-to resource for anyone searching for local businesses. In June 2010, Yelp announced that every 5 seconds, someone uses their mobile phone app to call a local business. During the month of May, Yelp for iPhone had over 1.4 million visitors.