You probably know about the free weekly download at iTunes. But there is also good free music to be had at my favorite local radio station (for music, that is. I prefer news content from ).
The only downside is that there is no automatic daily download. I find that if I open up iTunes on my computer every day, and have the podcast set up to download, it will do so for me. I usually hit refresh to get it going, but if I don't load iTunes on my computer, there doesn't seem to be any other way to get the music automatically.
I've been faithfully downloading KCRW's daily top tune for a few months now and I have a great selection of music that I can listen to. A lot of it is stuff I've never heard of which is great since it exposes me to new music that I wouldn't be able to find on my own.
And then there is also Pandora which I have not been keeping up with in a while because...well, because m started messing with the settings and so now I feel like the music they find for me is based on his tastes as opposed to mine. I've told him to quit touching my music settings on Pandora, but really I need to set him up with his own account instead.