TunA

from this wired article:

"Media Lab Europe, research partner to MIT Media Lab, is testing tunA, a software application that employs Wi-Fi to locate nearby users, peek at their music playlist and wirelessly jack into their audio stream. Pronounced like the fish and signifying music "tunes" and "ad hoc" file sharing, tunA is being designed for wireless PDAs, cell phones and even its own hardware device."

"When alone, a tunA-enabled device functions like a regular MP3 player. But around others like it, the interface displays other in-range users, identified by the avatar of their choice. Avatars appear or disappear automatically as users go in and out of range."

"Clicking on others' avatars lets you see whatever personal information or messages they want to share with the world. It also displays their playlist and the song they are listening to at that moment so you can decide if you want to tune in."

"There's also instant-message capability, the possibility to change skins and a virtual stalking feature: You can bookmark not only songs, but also people."

now why didnt we think of this?