Bluetooth for my phone?

Bluetooth is hilarious. First of all, there's the game "Bluetooth or crazy?", which is almost as fun as "moose or fox?". Second, there's the linguistic usage of Bluetooth, where it has become an aspect of your phone instead of a separate thing: you get "bluetooth for your phone", you don't get "a bluetooth headset to use with your phone." It'd be like your phone getting super-calling-powers or x-ray vision or something; all of a sudden, your phone "has bluetooth."

Language geekery and sidewalk games aside, I'm interested to know what a Bluetooth headset can actually do. In my mind, it's this totally-programmable other interface to your phone; basically a headphone and microphone, minus a cord.

Here's what I want: I want to be Captain Picard. I want to be walking around, and then just say "Computer: call someone" or "Computer: make a note. I had a thought just now that I want to save for later" or even "Computer: run this python script that I wrote." And then the computer (which is sleeping) would turn on when it heard its name, and do the thing for me. And I'd like the computer to be able to contact me, too; ring a bell or something. And by "computer", I mean my iphone. Or maybe android phone, because I'm sure it's more customizable.

Any of you ever played or hacked around with a Bluetooth earpiece? Can a Bluetooth do this all for me? Is there something better than a Bluetooth that I should be using? Will I become a "bluetooth AND crazy"? Time will tell. Either way, within the next five years, I will be pretty disappointed if I can't say "computer, make it so."