Score free MP3s from Amazon, Rhapsody, MP3.com

Are there any sweeter words in the English language than "free music?" (I know, "free pizza" runs a close second, followed immediately by "free beer," "free chocolate," and "free Tibet.")

If you're looking to stock your iPhone, iPod Touch, or Zune with some fresh, new tunes, you can find a mountain of free stuff if you know where to look. I'm talking legal free stuff, not the "free" tunes you pilfer from P2P services. Bad user, bad!

Rhapsody generously offers a free MP3 every day of the week.

As you probably know, iTunes gives away one song every week (gee, wow, thanks). Head to Rhapsody, however, and you can score a free song every day. And not just obscure tunes from little-known artists: Green Day's new "Know Your Enemy" was a recent download of the day (ahead of the new album's release, even), and yesterday's selection was Poison's classic power ballad, "Every Rose Has Its Thorns." (Couldn't...help...myself.)

Next, pay a visit to Amazon's MP3 store, which is home to a whopping 827 free downloads (and counting--the site adds new tunes every week). You may not recognize all the artists, but you'll find gems from the likes of Death Cab for Cutie, Flight of the Conchords, Iron & Wine, and Better Than Ezra.

Finally, CNET's own MP3.com offers a huge library of free tunes, though it's not a particularly easy library to browse.

Know any other good sources for free, legal, and worthwhile MP3s? Head to the comments and name 'em!

Update: Coldplay's new live album, LeftRightLeftRight, is available free for the download starting today. The only tricky part is connecting to the band's already overloaded Web site.