First off, a download that requires very little explaining - join their mailing list to get this new MP3 from the Indigo Girls. (Thanks Muruch!)
For a great selection of under-the-radar and up-and-coming artists all on one page, be sure to browse through the current Fingertips Top 10. Another can't-miss favorite of mine from this site is the track, "When Water Comes to Life," by Cloud Cult. Seriously, if you're going to give any of these a listen, make this one it! The group may be somewhat obscure, but this symphonic version of indie pop is pretty much "amazing" to the nth degree. Forget piano rock... let's use the whole orchestra! If you're familiar with Polyphonic Spree, you know the type of sound I'm talking about here - gorgeous and lush, and lively at the same time.
The indie chick in me is also really pleased about this huge variety of free music currently available on Amazon... Flight of the Conchords, Okkervil River, Neko Case, Jolie Holland, Death Cab for Cutie, oh my! "Bonanza" is a pretty good word for what's going on here!
Then for something a little more ethereal, with a touch of the ballad, look here for another Amazon download -- this one the song Lille by Lisa Hannigan. Beautiful!
Lastly, keep in mind that eMusic has an amazing selection of music for really affordable prices -- usually much better than amazon or iTunes. Currently, you can get 45 extra free downloads if you become a subscriber, and 25 free tracks just for signing up for the trial with no strings attached. They consistently offer a ton of free sample MP3s as well. I've been an emusic member for a couple of years now, and the only problem I've ever had is that I blow through my monthly quota of downloads too quickly. ;P Check it out, and download that new summertime barbecue or energetic jogging playlist you've been needing...
For more detailed ideas about free-and-legal sources of music, check out my other post Top 5: Free-and-Legal Music by the Mile (...bushel? ...gallon? ipod??)