You might be thinking of Opera Unite: http://www.operasoftware.com/press/releases/general/opera-unite-reinvents-the-web http://www.operasoftware.com/press/relea

You might be thinking of Opera Unite: http://www.operasoftware.com/press/releases/general/opera-unite-reinvents-the-web http://www.operasoftware.com/press/releases/general/opera-un... Didn't use p2p but allowed hosting own content. It's dead since long though.