Wow people just found this for the iPhone:
www.seeqpod.com
You can stream millions of songs right to your iPhone and it functions just like an iPod
all for free and legal!!
This is incredible. So how are these guys not being sued into oblivion. Imagine if the iTunes store could do this on your iPhone or Computer with movies/TV as well. Game Over man. Cool thing about this site is that this site just searches for music throughout the net. They don't host any of the files.
Also you can save the files if you want to. You can use Power MP3 WMA Recorder to record the song from the internet. Sucks you have to start and stop the recorder, but you will get high quality music from several places doing that.