Open up your new iPhone 4S, turn that baby on, and … where the heck is Siri? If you've waited patiently to try Siri since October, when the voice-controlled personal assistant feature for Apple's iPhone 4S first debuted, let us help you set up Siri and learn a little about it in the process. Here's what you need to know.

What is Siri?

Siri is a speech-recognition computer application unique to the iPhone 4S. It has speech input and output, meaning you can speak to it, and it can speak back to you. The software is technically in beta, so while it's functional, it does have some limitations. Read "What is Siri?" to learn a little more about Siri's history and its basic functions on the iPhone 4S.

How to Use Siri

Siri isn't an "app" in the iPhone sense, meaning it's not something you can download from the App Store, and it doesn't have an icon that you can press from the phone's screen to launch it. While Siri comes fully pre-loaded on all iPhone 4S units, you still do need to set it up properly. To learn how, read "How to Use Siri."

How to Teach Siri Your Name

In setting up Siri, you'll want to be sure you properly teach it your name, as well as all the people you call, text, and email frequently. Siri will have trouble with a lot of proper names, especially spelling, if you don't train it. You will also want to teach it relationships, so it will understand what you mean when you say, "Call my wife." For more, see "How to Teach Siri Your Name."

30 Questions and Commands for Siri

Now that you've set up the personal assistant and taught it proper names, you'll want to get a sense of what it can and cannot process, which is crucial in setting your own expectations for the software. When Siri was first released, we put it through its paces and saved 30 examples of short dialogues we had with Siri so you can get an idea of where it succeeds as where it fails, including its performance in other languages and dialects of English. Take a quick spin through "30 Questions and Commands for Siri" to get a sense of what it can and can't do.

Where Else Can I Get Siri?

Unfortunately, Siri is unique to the iPhone 4S model only, and, according to a report, Apple has no plans to add Siri to older iPhones (though rough workarounds are emerging). However, there are similar apps on the market, the most impressive one being Dragon Go! for iPhone. Vlingo is the other popular option. Dragon Go! can't do everything Siri does, although it can perform a few neat tricks that stump Siri. See "Apple's Siri Versus Dragon Go! and Vlingo" to find out how these three programs measure up.

Why is Apple's Siri Female?

When set to American English, Siri has a female voice. Why? PCMag investigated. In the U.K., Siri is male and "his" voice was recently revealed.

Advanced Uses for Siri: Controlling Your Home

Once you become a Siri pro, as Marcus Schappi clearly did, you might want to experiment to see just how much you can get out of Siri. Schappi hacked his iPhone to create a system he calls the Ninja board, which he's using to control nearly everything in his home, such as a lamp and his laptop computer. This article about Schappi's hack, with an accompanying video, shows the Ninja board in action.