Belkin's new "RockStar" is a simple star-shaped minijack hub to which multiple headphones can be connected, allowing one music player to send music to up to five pairs of headphones. An additional port is a dedicated input, while the other five ports can be toggled from input to output. That seems unnecessary to me—far easier to just switch the one dedicated input cable to the next player in the rotation.
While I can count the number of times I've wanted to get a group of people to gather around and listen to music on headphones on no hands, I still think it's a clever idea. I think there's a reason the hands in the stock photo are attached to children. Plus, it's only twenty bucks.
Belkin RockStar [iLounge]