Stream music from Android phone to PC over WiFi I've been searching on this site and can't find exactly what I'm looking for:
I have a PC (can run Linux or Windows) that's connected to my surround-sound speakers. When my friends come around they can listen to their music by connecting their phone to my speakers using a standard 3.5mm jack.

Is there a way that would let them connect their phone via WiFi to my PC and they could just play their music like they are connected directly to the speakers via a 3.5mm jack? One of the main requirements would be that they could use the standard music player in their phone.

Also does anyone know if this software or configuration this would require on the PC side to work?
There is a program that does this for the iPhone call shairport4w.  It basically uses the air play feature of the iPhone to play all audio through a wifi router to a pc running this software.

Edit: Ok so download Airstream. Then go to the PC you want to play from, and download Shairport4w.  You'll need the bonjour service from apple installed for this to work and if I remember correctly there is a way to install only the service without installing all of iTunes. I think it is get the iTunes full package installer and extract it as if it were an archive and only install the bounjour package.

After installing bonjour start shairport4w since it is only a small program running in the background. Then start Airstream. It should find your PC that has shairport4w running on it and then start playing whatever you want. It will go over wifi and play on the PC. I tried is using Amazon Cloud player and it worked great.

Edit: I've just added the links to the mentioned software. Though Kevin explains it the other way around (streaming from PC to Android, so he's probably rather referring to this Airstream app), the app I've linked above is the one for Android → PC streaming.

Edit (2):  This actually is stream any music player on the Android Device to your PC via WiFi.  The new name for the app is Allstream.  Look for it in the Play store.  Unfortunately for it to work, you're phone or tablet must be rooted.  I use it all the time since my Sound system is hooked up to my PC as it is a Media Center, and listen to Pandora, Google Music and Amazon Music from my tablet through the PC.