this cost less them 5$ shipped from dealextreme.com. a mic and an extension. a zip tie from the garage and
this particular headphone has a strong point to attach the mic- some headphones do-some dont. but a nice way to use quality cans and have a detachable boom mic
I've seen those "boom mics" on some low quality headsets that are detachable; they're just a small posable piece of flexible plastic ending in the mic on one end and a 1/8" stereo plug on the other (one connection for the mic, the other for the power) and had an idea like this in the past myself. I was planning to do this type of detachable mic mod to a pair of Sony V6 headphones I have (simply awesome things) but, I found a great deal on a Plantronics Gamepro 1 USB headset with a far far better mic than any of those low end ones could ever be.
Still a neat little "hack" project for those that are interested.
I just did that a while ago for my A900's it works great! The Mic is from a Tritton AX360 headset. I got an extra mic by calling customer support and saying mine died they just sent one. That company has crappy headsets but the customer support is GREAT!