Tap and hold the Home button to invoke Siri, or just raise the iPhone 4S to your face as if you were on a call. Speak your command or inquiry, and wait for Siri to respond. In apps with text fields, you can have Siri take dictation by tapping the microphone icon button on the keyboard (Android uses the same method for its transcription). I was amazed at how accurate Siri's voice recognition is, even with multiple people speaking and with background noise such as the radio playing. It's far better than Android's speech recognition, especially when it comes to dictation.
When used as a personal assistant, Siri does a good job of handling queries such as "What's my next appointment?" and "What are the directions to 501 Second Street?" With such basic queries, Siri figures out the context (such as the city you're in), looks up the information, and replies. Siri also asks you for context when it needs it, so the first time you say, "Call my mother," it asks for your mother's name to associate "mother" with a specific person in the future. It also shows you what it heard so that you can correct it as part of ongoing speech-recognition training. You can also use it to send emails, take notes, and add items to the Reminders task list. In these cases, you do need to use certain trigger phrases, such as "Send an email," "Take a note," and "Add a reminder" -- other forms of such commands are interpreted as Web search requests.
When searching the Web, Siri tends to favor shopping results when it doesn't really understand the question. For example, when I asked if I had enough cat food in the house, it responded with an offer to list nearby pet stores. It could figure out that the question was related to pets, but as it has no way of knowing what my cat food inventory is so defaulted to a list of providers, as it did with similar requests that required information Siri would have no access to.
Siri, of course, can also be used as a game, to see if you can fool it or elicit funny responses. (When asked what the meaning of life was, Siri told me, "I don't know, but I'm sure there's an app for that.")
Siri is not quite the "Star Trek" computer voiced by Majel ("Nurse Chapel") Roddenberry, but it's sometimes amazingly close, and it gets better the more you use it. It truly is amazing -- and useful.
App management. As you install apps, iOS simply adds them to your home screen, appending more home screens as needed, up to 11. iOS also lets you add Web pages to the home screens as if they were apps -- great for the many mobile Web pages that are essentially Web apps, such as m.infoworld.com, InfoWorld's mobile site.
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