Here is a cool example of building a multi-room music system DIY. The system is includes a file server where all music are stored, fanless Mini-ITX appliances which are used as clients and remote control (Nokia770).
The client is based on VIA ML6000EA Mini-ITX motherboard, which is absolutely noiseless and includes six-channel onboard audio, onboard LAN, support for 1GB of memory and a PCI slot. Instead of HDD it features 256MB Flash drive that plugs directly in to a 40-pin IDE slot. All those parts plus 256 MB RAM are placed into Casetronic C158 case.
Additionally, Embedded Gentoo Linux was built for each client. It includes Music Player Dæmon (MPD) to play music from the file server, lightTPD (a PHP-enabled Web server) and phpMp (a PHP application that controls MPD). This gives any computer on the network with a Web browser the power to control the client. As a controller is chosen an Internet Tablet Nokia 770. Using Opera, which comes installed, it can point the browser to each of the appliances and control them over my wireless network.
As result the author got a multi-room music system with noiseless clients (about $400 each) and cool remote (Nokia770, about $350). Which is not bad isn’t?