Does Cortana have an "always listening" mode so I can launch her without physically touching my phone, by speaking a specific word or phrase? Like Kinect has "Xbox", Google Now has "Okay, Google" and Siri will have "Hey, Siri". This would be handy when driving, for instance.
Yes, the Lumia Denim firmware update will enable a voice-activation feature called "Hey Cortana" on supported phones. You'll have to switch it on in your phone settings, and then train Cortana to recognise your voice, after which you'll be able to activate her without touching your phone.
For more information, see the following links:
- 'Hey Cortana!' brings passive-listening to Windows Phone this fall for a hands-free experience
- Hey Cortana: Limitations, How to train & Battery saver
It seems Microsoft may be planning to add this feature to Cortana, as explained in this article on WPCentral. Apparently Marcus Ash, the Group Program Manager for Cortana, teased this feature on Twitter (emphasis mine):
WPCentral goes on to speculate, however, that voice activation may only be supported on newer devices with Snapdragon 800 and higher chipsets. As of the writing of this, that would only include the 1520 and the 930 / Icon.
Update: Voice activation has been confirmed to be a part of the upcoming Lumia Denim firmware update, scheduled for release later this year. As suspected, it will only be available on phones with Snapdragon 80x chipsets.