If you press the command key and click on the title of the streaming channel you're listening to in iTunes, Safari starts, opens up a new window and goes to the web page.
I found this trick listening to Dr. Horner's Classic Jazz Corner, , where current song and recent playlist is shown. I think it's great!
[robg adds: Although the original hint made reference to this only working in Safari, I tested it by changing the default browser in the Internet preferences panel, and it worked with Mozilla, OmniWeb, and IE in addition to Safari ... I didn't bother testing the other OS X browsers, but I assume they'd all work.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20030301144002385