Dijjer is an alternative P2P tool to host large video/media files like BotTorrent. So if you want to host a large file on your site, you can upload it at http://mysite.com/video.mov and give the users a download link -http://dijjer.org/get/http://mysite.com/video.mov. When they click a Dijjer link, users will get some of the file from your website, but most of it will come from other people running Dijjer. That’s how you save bandwidth. And when someone clicks on the link who hasn’t used Dijjer before, they’ll get help installing it. The major differences betweek BitTorrent and Dijjer is that Dijjer does not require a client, it runs through the web browser. This is useful in companies where random ports are blocked and only port 80 and 443 are open.
Apart from that, you can even preview the media files as they are downloaded.

Dijjer Homepage