Someone at Google must like Airtime as much as we do, because it just added a roughly equivalent YouTube party mode to Google+ Hangouts. As long as everyone has the web app running, they can share individual videos or whole playlists that run in sync. Any set of videos is shareable through Google+ or YouTube proper. Voice chat, mercifully, flips to a push-to-talk requirement to prevent friends from talking over your favorite clip. While there's no accounting for taste in what you play, Google can at least promise immediate, worldwide support for your group cat video sessions.