• by Mark Walsh  @markfwal, October 4, 2011

Apple on Tuesday unveiled the latest incarnation of its signature device -- the iPhone -- but the modest upgrade didn't necessarily reflect its long delay. Released months after it was originally expected, the iPhone 4S is similar in design to the prior model, but packs a faster dual-core A5 processor, 1 gigabyte of RAM and a new camera with more advanced capabilities.

The most attention-grabbing feature of the new iPhone, however, is Siri, a voice-controlled feature that serves as an intelligent "personal assistant" that helps you get things done just by asking.

In a demo of the service at the Apple press event, Scott Forstall, the company's senior vice president of iOS Software, asked the phone what the weather was today. The phone answered: "Here is the weather for today," showing the weather screen. Siri can also make calls, send text messages or email, and schedule meetings and reminders.

The iPhone 4S runs the latest version of the device's operating system, iOS 5, which includes Apple's iCloud service for digital media storage. It also features a new Notifications Center for managing notifications in one place. Swiping a notification will take a user to the app associated with it to respond accordingly. iMessage, the messaging service Apple announced in June at the same time as iCloud, is also part of iOS5.

The new 8-megapixel camera boasts 60% more pixels and a new custom lens for sharper images. New photos can be shared instantly via built-in Twitter integration and iMessage. The new iPhone also allows video recording in full 1080p HD resolution, the highest standard available.

In addition to providing twice the processing power, Apple said the new A5 chip delivers up to seven times faster graphics than iPhone 4, which should be good news for video game enthusiasts. It also supplies battery life for up to eight hours of talk time on 3G networks.

The release of the original iPhone 4 sparked a controversy dubbed "Antennagate" because the external antenna caused reception problems for some users. The iPhone 4S has a redesigned antenna system that switches between two antennas for improved call quality and higher connection speed. The phone will have download speeds of 14.4 megabits per second and upload speeds of 5.8 megabits a second.

Pricing for the iPhone 4S starts at $199 for 16 gigabytes of storage, $299 for 32 GB, and $399 for 64 GB. An iPhone 4 with 8 GB will sell for $99. And the iPhone 3GS will be offered for free, with a two-year contract. Preorders for the 4S start Oct. 7, with delivery on the 14th. The iCloud service will launch two days before that.

The iPhone 4S will roll out worldwide to 22 more countries, mostly in Europe, by the end of October. In addition to AT&T and Verizon Wireless, Apple confirmed that Sprint will now also carry the iPhone in the U.S. The Wall Street Journal reported Monday that Sprint committed to spend $20 billion for 30 million iPhones over the next four years.