On my previous Nokia there were two input reader programs (eg.magickey) that were allowing you to change the action of a specific key either on a global profile, for the entire device, or for certain applications, chosen by you. However none of these programs could "sniff out" the headset input. The only guys to almost master this function were the guys at mobifactor.ru - 4 out of 5 buttons. CorePlayer could recognize one aswell... but those are ol' symbian times