Zattoo is a compact client which makes it easy to watch around 20 TV stations on your own PC.
The range of channels isn't particularly surprising: lots of news content, for the most part (Al Jazeera, Bloomberg, Russia Today) with a few more general channels thrown in (STV, Ulster TV).
If you're not sure what to watch, then an electronic program guide is available to help you figure things out.
Or a Preview option will show you thumbnails of what's currently on each channel, a quick way to see what's interesting and what really isn't.
You do need to sign up for a free account to use the software, unfortunately, and they'll show you their own ads every time you switch channels.
Still, if you can live with that, and the channel selection is to your taste, then Zattoo might be interesting.