Enjoying viral internet videos with your friends is fun, but somewhat awkward over instant message. YouTube Social lets you and your friends watch videos at the same time and chat through one unified web interface.
Usually, sending a YouTube video to your friend over IM means the conversation will have a lot of "did you get to the part where...?" type phrases. However, if you want to enjoy the video with them at the same time, YouTube Social gives you a neat interface in which you can do so. Just head to any YouTube video and add social in between youtube and .com in the URL (i.e. http://www.youtubesocial.com/watch?v=o_NUKxjBlKI). Alternatively, you can search through YouTube's database straight from youtubesocial.com.
From the YouTube Social interface, the party initiator can control the video, though you can hand off control at any time by mousing over a friend's avatar and hitting "Give Remote". You can also chat with your friends about the video as it plays in the chat box on the right-hand side. You can also get rid of the "guest" chat handles by connecting with Facebook, if you so choose.
Despite the somewhat cluttered interface, it's a pretty neat service — the only trouble I had was that if I handed off control and they rewound the video, sometimes it would stop playing in sync, thus defeating the whole purpose. But, overall, it's pretty neat, and if you don't plan on messing with the controls too much, it works pretty well. Check out the video above to see it in action.