Pedro Alcocer explains How to never miss an episode with BitTorrent and RSS.
As it happens, I first installed BitTorrent this weekend (to get an update to the Ubuntu CD I picked up at the Python Meetup). I was very impressed with the BitTorrent technology. Before I had even finished downloading the Ubuntu image, I was serving parts of it to other clients.
So when I saw the description of using RSS with BitTorrent to automatically download episodes of TV shows, I figured I'd look into it. TvTorrents implements the idea well: torrents are available for many shows, organized by year and episode. Each user has to login to download, and a credit system is used to ensure that downloaders also provide upload bandwidth. I haven't read about the details of the BitTorrent protocol, but it seems to have been very well thought out if credit systems like this can be built on top of it.
Of course, sites aggregating TV episodes and offering them for download are illegal, and I'm sure the TV industry is taking steps to bring them down. But it is thrilling that free open source technology is available which can be used to build services like this.