This is my favorite feature in the new iPhone 6S

Siri can be a pretty useful personal assistant, but asking her questions is a much better experience when you don't need to use your hands.

That's one of the unique features of the iPhone 6S: You can program your phone to listen for your voice, so Siri can activate whenever you say "Hey Siri" within earshot.

I've used this feature every single day since the iPhone 6S launched last month. I find it incredibly useful.

It's particularly good to use while you're getting ready in the morning. While I'm walking around, eating food, brushing my teeth, looking for clothes to wear - even looking for my phone - I can shout out "Hey Siri" and ask it things about the weather, or what meetings I have that day.

Apple highlighted this new feature in a fun 30-second ad with "Saturday Night Live" alum Bill Hader, who also appeared in an Apple "backstage" video that appeared during the company's Worldwide Developers Conference in June. 

You can check out the ad below. It gives you a pretty good idea of how well the "Hey Siri" feature works on the iPhone 6S.