Cortana can be more useful if she could be invoked with a voice command and to do so just add

5555559876 as a phone number and call it "Cortana" or whatever you like.

Then you can 'dial' Cortana' and interact via Bluetooth as you can on the windows phone itself.

 

Anything Cortana can do she can do blue!

I have the updated version of cortana its full of senseless chat & never wrong = SWMBO