This is something a ROM dev has to fix with the phone. Ultimately, it's only going to be able to happen with a rooted Droid. Recording both the speaker and microphone hardware is simple. It has to have been disabled within the phone.
Droid: UD Extreme 7.0 driving a Chevy ULV 125-1000
Xoom: Rooted, Overclocked, SD enabled, Themed,ready for da biznich...