You can find a number of wireless devices at any electronics store deisgned for this purpose. I have an iMac connected to my stereo using an Airport Express. They're about 30 feet apart. It works well. Haven't tried other brands but you can look into them - there are several.
I used to have my PC connected to my stereo via a cord (I believe it was plugged into the speaker output on the back of the computer). However, I was wondering what options there are to WIRELESSLY connect my PC to my stereo receiver and thus play music through my PC onto my home stero system. I am interested in keeping this cost below $100 if possible. I currently have no aspect of my system hooked up wirelessly. Thanks.