It came from eBay often focuses on weird and ridiculously overpriced auctions on eBay, but today's item is a little more affordable — it's just useless.
This weird game-development trinket is a GameCube NR (not retail) disc. If you've ever seen a debug console or pre-release build of a game, it was likely on one of these. It's simply a branded burnable disc. In the GameCube's case, anything put on an NR was actually primed for testing and debugging, but only the NR reader could boot up information in this format.
Even if you tracked down a reader, this disc is still pretty useless. The one featured above is apparently blank and currnetly on auction for $25. If you were extra determined, I suppose you could use this in your ongoing GameCube indie development.
While researching this disc I stumbled across an amazing piece of information: Did you know the GameCube supported stereoscopic 3D? The first and only game to utilize this functionality was Luigi's Mansion. Quick, someone with a 3D television test this!