Metastream - Watch streaming media with friends
Giggl - Browse the web together with anyone in real time.
Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
Invited.tv - Watch together from anywhere and hang out with friends online
Hyperbeam - A better way to watch together online
Couchmate - Chat about live TV, together!