In a press release today, Apple announced that it has already sold 4 million iPhone 4S units during the device's launch weekend. In addition, the Cupertino-based company announced that more than 25 million users have upgraded to iOS 5 in the five days that it has been publicly available. Finally, Apple announced that more than 20 million users have signed up for iCloud, the company's new cloud services offering that replaced MobileMe. 

"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. “iPhone 4S is a hit with customers around the world, and together with iOS 5 and iCloud, is the best iPhone ever."