I just remembered this interesting tidbit regarding the use of the microphone on my shiny new iPhone headphones with my shiny new MacBook Pro:
Yes, it’s true—these new MacBooks work with your iPhone headphones. If you click the button on your iPhone headphones, iTunes pauses. Click again, and the music resumes. A double-click advances one track, and a triple-click moves back a track—just like on the iPhone. What’s more, the headphones’ built-in microphone appears as the input device “Microphone port” in the Sound preference pane.
At the time this was published, I didn’t have an iPhone or a compatible Intel Mac so I didn’t pay much attention. Now that I do, this is pretty nifty.