Most of the time that I was in my apartment in Japan, I used to play local TV and radio in the background. Not only did it help with my Japanese pronunciation but it also gave me the ability to make all of those interesting exclamation noises that Japanese people make. ("Heeeeaaaahhh!") The music was usually pretty good plus, because I wasn't fluent, the radio banter was never a distraction.
Anyway, I just came across the website RadioBeta (via Lifehacker) which streams radio from around the world... including Japan!
Also, if you're interested in some Japanese TV, I came across this site while I was looking for ways to stream the Olympics. They have a few Japanese TV stations and, occasionally, even their Fox Japan stream works.
Fox: Japan Number One!