Sony announced today that they will cease production of the MiniDisc Walkman this fall due to a drop in demand.
If you're wondering what's a MiniDisc, you're not alone. Like the Betamax and Memory Stick, this was one of Sony's many proprietary technologies that hardly any company besides Sony used. It was invented in the early 1990s as a more compact alternative to the already popular CD, but it never really caught on. I'm not sure that any company besides Sony used it.
Now, the MiniDisc Walkman might be dying, but the MiniDisc will still be made. This 6cm disc will still be available online and well, that's probably the only place you can find it in the US.