Folks at a company called GeekRoo had the idea of fitting all the messy bits needed to run a Raspberry Pi, including the Pi and lots more, into one neat box.
The result is a mini-ITX-compatible PCB that will go into a mini-ITX box, or a custom acrylic box.
Onto that 17x17cm PCB is built a power supply (3.3, 5 and 12V) and an Arduino UNO. "You can use this built-in Arduino to control the ON/OFF of the Fairywren, or talk to the XBee, or control the cooling fan," said Geekroo.
Fairywren is the name of the PCB, named aftr a small active Australian bird, and there is room on the board for a Raspberry Pi, and XBee, and also "you can mount either a 2.5in HDD or a standard Arduino on the Fairywren board", said GeekRoo.