Siri

Yes, I got an iPhone 4S, and it's wonderful in all kinds of little ways.  But the big way is Siri.  Wow.  Yesterday evening I looked at my children and thought hmm, they need haircuts.  Pulled my phone out of my pocket and said "Remind me to call Kids Club in the morning."  Siri said, "What time would you like me to remind you?"  I said 9am.  She created a reminder and said, "Is this right?"  It was.  At 9am, of course I had forgotten all about it and Siri reminded me.  I picked up my phone and said, "Call Kids Club."  She did.  I discussed the haircuts with them, made an appointment, hung up, said "Make an appointment for haircuts tomorrow at 4pm."  She said, "Here is your appointment.  Were you aware that you have two other appointments at that time?"  Wow.  (They were nothing, but they were on my calendar.)

I said, "Remind me to bring Aaron's snacks to school on Monday morning at 8:30."  She created the reminder, and then I realized that 8:30 was too late, so I said, "Change that to 8am."  Done.  I was cooking and said, "Set the timer for fifteen minutes."  Done.  I asked her, "Is there traffic on I-5?" and she said, "Here's the traffic," and opened the Map app to I-5 near my location.  She can remind me to do something when I arrive at a certain location, or leave a location -- as in, remind me to sign that permission slip when I get to Aaron's school, or get gas when I leave work.

I asked her, "What's the tallest building in the world?"  and she gave me an extraordinary, glamorous WolframAlpha answer, with the pertinent information right up top and everything else I might possibly be wondering about that building or various other tall buildings in a beautiful, accessible layout.  

She doesn't hear perfectly; in the car with the radio on and the kids yammering in the back, I wasn't getting anywhere.  But most of the time she hears just what I said and responds with astonishing helpfulness.  I think the whole system is actually better than advertised.