I picked up an EH25 on Ebay. It was 3.99, but now it's 6.99 (includes shipping).
OEM Motorola EH25 Stereo Earbud MetroPCS Motorola VE440 The description said it came with a case, but it doesn't. It's just the headset with 4 foam earpiece covers you can put over the earpieces, a shirt clip, in a tiny ziplock bag. They are black wires with blackish/very dark purple speakers and mic. I tried to attach a picture. I didn't see a button on it at first. After a playing with it a while, I just squeezed the mic in the middle and it clicked. The button is inside the aluminum casing. It's like you squeeze a soda can, it bends and it clicks the button inside.
I have the HTC Droid Eris and it will mute/unmute when you are on a call. It will pause/unpause if playing music. For fun I clicked a bunch of times and it called the last person I called. ahaha so be careful how many times you click it.