WiiRadio is a ShoutCast stream player. It can read from thousands of internet radio streams and play them back on the Wii.
Here is an important message from the developer, regarding the latest version:
3/12/09 – Currently it appears that WiiRadio is not retrieving stations. This is due to a change on shoutcasts playlists page. I’m working on fixing this. Unfortunately I was in the middle of hacking up the code when I noticed it not working so it’s going to take a little while to get out the next version (maybe a day or two). The good news is that playlists will be supported in version 0.2. This includes reading them from the SD card and saving them to the SD in the PLS format. So any playlist you save from WiiRadio will be compatible with Winamp. – I know quite a few people have asked for this.