With lines to grab the latest iPhone as mad (and weird) as ever, there wasn't any doubt of boffo sales numbers for the iPhone 4S. But on Monday morning, Apple announced in a press release that the phone is doing very well in sales, topping 4 million units shifted in its first weekend. "iPhone 4S is off to a great start with more than four million sold in its first weekend-the most ever for a phone and more than double the iPhone 4 launch during its first three days," said Philip Schiller, Apple's senior vice president of Worldwide Product Marketing in the release. The statement also informs that a slew of customers worldwide will be granted the opportunity to update their smartphone to the Siri phone on October 28. The strong early sales gives the iPhone 4S a strong shot of taking over the Guinness World Record for fastest-selling consumer gagdet that currently belongs to Microsoft's motion sensor for Xbox, Kinect. It sold 10 million units in about four months after it was launched last November, beating out Apple's iPad for the sales record crown.