Stephen C Phillips made a simple UPnP / DLNA enabled media hub with Raspberry Pi and Android phone. The project concept is simple, it is a good alternative of Apple Airplay. You can play music anywhere in the house, music streamed from another computer in the house, using Android phones as remote controls.
What you need:
A Raspberry Pi
A wireless USB dongle (or wired ethernet connection near your Hi-Fi)
N150 Nano USB Wireless Adapter from Maplins for £10
A micro-USB power supply
An SD Card (2GB minimum)
An SD Card reader/writer