This build is based around Paul Carmody's excellent Overnight Sensations speakers.
I added an integrated TA2024-based amp, an ipod Dock, an PCM2704-based USB DAC, integrated bluetooth, and 5 RGB LEDs controlled by a TLC5940 (12 bit PWM resolution per channel!).
The whole thing is controlled by an atmega32u4 and uses an IR remote for user interface (no buttons on it except for a volume control pot/switch).
I am making the enclosures out of MDF, and the PCBs (only single-sided!) using DIY methods.
I am planning to laser-cut the display panel out of acrylic.
The arduino controls the ipod using serial, the Leds with cool effects and a vu-meter, the audio source, the bluetooth module via SPI, and there is a usb hub on board to service the ipod, souncard, and arduino for reprogramming.