Cisco Headset Adapter for iPhone Headset
I use it with my Iphone headset so I don't get tired for long hours on the phone. I stopped using my wireless headset, or very little. :-) I use it with the Cisco VOIP phone at work. I would definitely recommend. It works out of the box. I even told my friend to get one for himself. I didn't mind the yellow color.
It's works as advertised. It does exactly what you expect it to. I'm using it with Etymotics Hf2 earbuds and a Cisco 7941 phone. I did confirm that the button on your iphone line mic does not do anything, but I don't think that's a limitation of this adapter. It seems none of the cisco headsets have any kind of button on them, so I guess the cisco headset port doesn't support anything.