World Radio Lite gives you access to one hundred online radios. This app is the free version of World Radio, which you can access to listen to a bunch more radios than the free version. World Radio Lite couldn't really be any simpler. It is a window that lists one hundred stations and you can click on any of them to play them.
There are different genres available and from the name of the radio stations you can guess what type of music they will be playing. There are 80's and 90's channels, top hits, dance, techno, pop, and rock music, to name just a few genres. You can also add stations to your favorites list. There is a search feature to quickly get to the station that you want. These features are probably better for the paid version which has a whole lot more stations than this one, though.
If you have Growl installed on your Mac, every time the song changes, you will receive a notification showing you the name of the station, the artist and the song.
All in all, this little application works very well. The radio stations load really fast and I didn't experience any playback problems, when I was testing it.