I have avoided getting RealPlayer because, once you load their program, they blast you with ads for their own and other products. There is fortunately an alternative - specifically called Real Alternative. Go to this web page:
http://home.hccnet.nl/h.edskes/finalbuilds.htmLook for "Real Alternative." It combines the "Media Player Classic," a non-fancy player program very similar to the original Windows Media Player, and codecs and things that will play most RealMedia content. You have one tricky part; you have to point the web page part to where your web program is, and the program gives you hints for that.
I can testify that the program plays AirAmerica and a lot of other Real content with "unReal" quality.
While you're there, you can also get "QuickTime Alternative," which does the same for QuickTime (which I admit I haven't tried yet). At this point, I don't know if the author is preparing something similar for the Mac. (Just so you know, I have both flavors of machine.)