The DualDisc

The first DualDiscs – double-sided hybrid discs which have regular CD audio tracks on one side, and DVD music or video on the other – are being test marketed in Boston and Seattle (just look for the logo!). The big downsides: the discs are a bit thicker than regular CDs or DVDs, so they might just jam your player, and some PCs are said to have trouble recognizing them.

[Via HomeTheater.About.com]