I plugged in my iPhone headphones to my laptop, which has the little microphone/click button that lets you skip songs, pause the iPod or answer a call. Well I was watching a DVD rip, squeezed the button, and it paused it. Gasp. The headphone jack is a four-conductor jack like on the iPhone.
And the microphone works too. That explains why Diana could actually hear me while doing the Skype the other day.