FStream works well, but I find that WunderRadio works even better. However, FStream is free, so let's start there.
Download FStream from the App Store, then open it. Press Favorites, then press Edit in the top left corner. Now press "Add new webradio". Type "DIS Radio" in the name box (it can be whatever you want), then in the URL box type:
"http://www.live365.com/play/dreamsunlimited?tag=terra" (be sure to leave the quotes off). Leave the Format and Bitrate boxes blank and press Save at the top right.
Press the "Play" button at the bottom left, then press where it says DIS Radio. This should start it up and you should hear music in a few moments.
The URL above can be used with any Live365 radio station; all you need to do is swap out "dreamsunlimited" with the user name (not the radio station name) of whatever radio station you are trying to listen to. For example, Mouseworld Radio's user name is "torg0". So, in order to play Mouseworld Radio, the URL would be "http://www.live365.com/play/torg0?tag=terra".