looking for internet music program

Hello,

I am looking for a program that can synchronize the music playing on two computers. My friend and I play a lot of online games together while on the phone or using Skype, and he thought it'd be cool if we could have our computers playing the same music at the same time.

I don't want to set up an internet radio station or anything big like that, and we want to be able to play music from either of our computers and have it stream to the other. I saw a program like this for LAN a long time ago, but I completely forgot what it was called (I think it was something short, like two or three letters).

If anybody could point me in the direction of something like this, it would be greatly appreciated.