Cellular headset pinout

[Steve]

I can't believe I couldn't find this on the site... but I am looking for the pinout for a standard cellular headset... the standard I am talking about has a 2.5 mm 3 conductor plug that handles microphone, mono speaker, I assume some sort of ground, and some way of telling the phone to answer or hang up (probably interrupts the ground or something for that... I don't know)

Help?

Steve

adventurer@bigfoot.com