Feel free to jack into my plug
iPod users share audio ports with iPod-enabled passerby, envision wireless sharing via Bluetooth and Rendezvous in the future:
Sharing an iPod through its headphone jack is also a crude, low-tech version of what some predict is the real killer application of future iPods: transforming them into short-distance broadcasting devices by adding Bluetooth or similar radio technology, coupled with Rendezvous, an Apple-developed networking technology that allows devices to discover each other automatically