I think this is a new, never-before-seen product that Apple seems to be working on: In a patent filing made public today, Apple calls it a wireless headset with integrated media player. What it looks like is a Bluetooth-enabled iPod that can connect to your iPhone, but also has integrated memory for playing back MP3s, and a microphone for allowing you to talk and make audio notes to yourself that you can then save to the device.
In one permutation of the device, it could be operated using voice commands, and with one or two earpieces.
Some descriptive language from the filing:
"The media player may be an audio player, capable, e.g., of playing audio files such as MPEG-3 ("MP3") files. Optionally, the media player may include a recording function as well, so that a user can record voice notes. In addition, if the headset is being used with a telephone (mobile or landline), the availability of a recording function could make it possible for the user to record all or part of a conversation. Similarly, voicemail messages received on the user's telephone could be uploaded into the headset for later off-line playback."And some more description:
Alternatively, given the presence of a microphone in the headset (primarily for use with a telephone), the media player could be configured to respond to voice commands, which could allow more complex commands, including commands to play particular content. In addition, the microphone could be used to detect the ambient noise level, and to adjust playback volume accordingly.