Improved techniques for communicating between a portable electronic device and an accessory (or auxiliary) device are disclosed. The accessory device can augment or supplement the functionality or capabilities of the portable electronic device. For example, in one embodiment, the accessory device can provide wireless communication capabilities to the portable electronic device. In one embodiment, the portable electronic device pertains to a portable media player and thus provide media data for storage, playback or transmission. In one embodiment, the accessory device is attachable to the portable electronic device.