Android: XDA TV producer Kevin (aka The Tech Ninja) came up with a way to make his phone as hands-free as possible. He uses a combination of Tasker commands, Autovoice and a few other apps that can launch specific actions when he presses the command button on his Bluetooth headset.
Essentially, Kevin has multiple tasker actions that are triggered by Autovoice commands. As an example, in the video above, he sets up a Tasker action to vibrate his phone every time he hits the command button on his headset and says "bananas". It's not incredibly useful, but it shows you what the combination of apps can do. A paired Bluetooth headset can pass audio commands to the phone, Autovoice can recognise them and pass those commands on to Tasker, which can do different things based on the command it's given. The hard part isn't even the Bluetooth-to-Autovoice configuration, it's the Tasker actions you would want to set up, and we know you have some suggestions in that department.
You can see the finished product in the video above, including some of the specific commands he has Tasker and AutoVoice set up to recognise on command, such as "GPS off", "Launch Google Now", and commands to send "on my way" messages or put his phone in "night" mode. Kevin includes a number of other apps to extend the voice functionality he set up, including SMS, My Car, and Me and SecureSettings. You don't need them all if you're trying to duplicate what he has, but they might be helpful.
Voice Control Your Phone with Tasker and AutoVoice [XDA Developers]