Airfoil - This software is from the Rogue Amoeba company, built to run on Mac and Windows platforms. It’s an audio-based software that allows the computers sound to play over a network device. Read more about Airfoil.
Spotify - Map shows when two people play same song at same time
AudioRelay - Listen to your PC audio, use your phone as a mic or stream audio from your phone
Last.fm - The world's largest online music service. Listen online, find out more about your favourite artists, and get music recommendations, only at Last.fm
Stream What You Hear - Stream What You Hear.
SoundCloud - Enjoy music & follow favourite artists