Apple has announced that they sold over 4 million iPhone 4S units on opening weekend. This is more than double the sales figures of the iPhone 4 in its first weekend last year and right on par with estimates that analysts set for the device last week.

More than 25 million customers are already using iOS 5 which was released for compatible iOS devices last Wednesday and over 20 million people have created an iCloud account.

"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."

Despite what many perceived to be an underwhelming product launch, it's clear that millions of users are still clamoring to get their hands on Apple's latest handset.

Last week we reported that pre-orders for the new iPhone had topped 1 million in just 24 hours. Most analysts figured Apple would sell between 2 million and 3 million 4S handsets on opening weekend but Carl Howe from Yankee Group takes the prize as he pegged Cupertino to move 4 million units.

The 4S went on sale October 14 in the US, Canada, Australia, the UK, France and Germany. For the first time ever, the phone launched on three of the top four US mobile carriers; AT&T, Verizon Wireless and Sprint. 22 more countries will get the 4S on October 28 with 70 countries having availability by the end of the year. It comes in three sizes: 16GB for $199, 32GB for $299, and 64GB for $399 with a two year service agreement and is available in black or white.