Netflix Party - Netflix Party is an extension for watching Netflix remotely with friends and family for movies nights with that long-distance special someone.
YoutubeMultiDownloader - Just like its name YouTube Multi Downloader, it is an online website for downloading the videos of downloading without using any video download and accelerator.
Hyperbeam - A better way to watch together online
KeepVid - A free web application that allows you to download videos
Metastream - Watch streaming media with friends
ShareTube - Watch YouTube, synced with friends.