Foobar2000:Components 0.9/Cover Flow (foo bubble coverflow)
The plugin can work either as a UI panel or a standalone window (found in the view menu), and a fullscreen mode for both. I'll make it a UI element when the SDK for it is available. For now it is only able to display art stored in external files, not embedded covers.
The plugin uses OpenGL for rendering, and if your hardware support it, Full Scene Antialiasing is used to eliminate jaggies.
You configure the cover source in the configuration panel (right click in the window for the configuration). The default is folder.jpg.
The cover flow display is a view of the active playlist, and works much like the itunes component. Acting on the active playlist affects the Cover flow and vice versa.