Use WiFi Speaker to stream all audio from a computer to an Android device in realtime. Just run the server on your Windows PC, and the app on your Android. The server is completely free, as is the app.

Setup is easy.

1. Download and install the server on your media PC.
2. Get the WiFi Speaker Android app on Google Play
3. Enjoy tunes!

Server download:

XP/Vista/7 (2.3)

Server requires: 512MB RAM, 100MB disk space, sound card, and .NET Framework 3.5

Pro version of android app released! 90% compression, no voice interruptions, No ads, and equalizer control!

For detailed instructions and FAQ, check out the WiFi Speaker Guide.
And here's the Android App user guide.

Future Features:
-Native clients for Windows PC, Mac, and Linux almost done. Expected release: April.

Other Apps:
Text Message Spam - Sonic SMS
Best Static Free - Live Wallpaper

Recent changes:
02/06/2013: v2.3 Min latency now 10 ms. Bug fixes.
12/19/2012: v2.2 Bug fixes, Logging, GUI changes
11/28/2012: v2.1 Less latency, client table fixed
11/27/2012: v2.0 Bug fixes, less CPU usage, less breaks in audio
11/18/2012: v1.5 Bug fixes, buffering and animation improvements.
11/11/2012: v1.2 Cleaned up, error logging, added passwords.
10/31/2012: v1.0 Initial release.