foobar2000 - An advanced freeware audio player for the Windows platform.
Jelly Party - Watch anything together.
BeatSense - Discover great music hand-picked by real people, in a single click. FREE and in real-time!
SOUNDS - Discover music with friends
noidd.com - Enable users to share music and videos LIVE with others people on customizable channels.
Hyperbeam - A better way to watch together online