possible to "push to talk" using iphone's headset? I use my iPhone a lot for business calls.  Improper use of the mute button could be a career-ender.  Is it possible to use the iPhone's headset to toggle the mute button?

Thanks!
Unfortunately the answer is no this isn’t possible however you could look at whether you could find a push to talk set of headphones and microphone. Basically with a physical switch to mute. 

And there’s always the mute buttons in call.