Zattoo allows you to watch TV channels on your PC for free. Most of the channels are local to where you live but there are a selection of free international channels such as Bloomberg and Press TV.
After registering for a Zattoo account online and installing the client, you'll get an overview of the available TV stations in your locality. When you click on a channel, you have to sit through a 10-15 second advert which is a bit annoying but after that, the streaming is uninterrupted. Streaming is very stable and image quality is very good.
Zattoo also has a TV Guide which helps you plan your viewing schedule and see what's up and coming and you can search for specific channels. There are very few features or options beyond that, however. There are no quality settings and no way to change the language of the interface either which is a bit annoying. There's also no way to make recordings of programs in Zattoo, which would be useful.
If you don't have a TV at home or want to watch local TV on the move, Zattoo is an excellent solution.