What is it? This, my friend, is a remixed version of Limor Fried's excellent Arduino Wave Shield, in cube form. I described it to my daughter as a kind of clunky, impractical iPod. It will read WAV files off an SD Card and play them back. Because playback is controlled by the Arduino-compatible top of the cube, you can hook up all sorts of buttons, sensor, joysticks, etc. to control which sounds are played when and at what speed. It also has an Xbee antenna on one side so the boxes can talk to each other and trigger each other's sounds over a mesh wireless serial connection.
Unfortunately, this is a limited edition for a particular project and not available as a kit.
All the solder joints on the inside hold the thing together and act as signal connections between the faces. You can get an idea from these pictures:
Oh, and all the Eagle files are available here:
