I just read an article about synchtube, a fantastic site that allows you to watch YouTube videos synchronised with your friends.
There is no registration, so you can quickly set up a room for you and your friends to use, with a unique URL for your room. There is also a chat area so you can discuss the video while watching it.
Something I think a lot of people may take for granted is the ability to load a new video without having to create a new room. That feature could have been easily overlooked.
However, I think there is only a limited use for synchtube. It will not take long for the novelty to wear out on an idea like this.
Short URL: http://arteki.com/xhqdc