SopCast is a P2P technology–based program that will let you turn your computer into a real television channel.
With it you can stream videos of the location, file, or directory of your choice. Other Internet users will be able to access the contents of your broadcasts, and the more that people watch your channel, the better the reception and image quality. To that end, the video to be broadcast must be in one of the following formats: ASF, WMV, RM, MP3, SPL...
On the developer's webpage you can advertise your channel to other users, put it in a category, and decide who will have access to it (public or private).
With SopCast you can also watch other users' channels. To do so you just have to click on the link of a certain channel and it will play on the player integrated into the program. You can also watch TV channels from across the globe.
The main advantage of this program is its ease of use: you don't have to configure anything. For once you can forget about those damned ports. (Unless you want to create your own television channel, then you will have to configure certain parameters.)