Just playing around with the new “hand off” (I guess this falls under) feature in IOS8 / Yosemite. If you have a phone number in a web page suitably marked up as <a href=”tel:…”>link</a> and visit that page with Safari, clicking on the link will automatically send you to the FaceTime calling application which will start calling the number from your (i)phone with the audio piped through your Mac. Very neat trick!