Turntable.fm - Turntable.fm is a social media website developed by Billy Chasen and Seth Goldstein that allows the audience to stream their own music.
CyTube - Free, open source synchtube
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
Metastream - Watch streaming media with friends
Kompoz - Kompoz is an online platform for crowd-sourcing music creation, making you record, create or publish music with the guidelines of a world-class musical expert.
Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.