Free MP3 downloads - no limitation, no spyware
First source : CNET
Remember the name - Fort Minor (http://music.download.com/fortminor/3600-8520_32-100769615.h…)
D.A.N.C.E - Justice (http://music.download.com/justice/3600-8362_32-100861121.htm…)
PS: Lots more music to download here, but takes a while to find because a lot of the songs are free preview only.
Second source : Emusic (requires credit card to signup for trial account)
Free 50 mp3s
PS: The link below contains my referral id so you get 50 free mp3 and 50 free download credits go to my account
(http://www.emusic.com/?fref=300030)
If you do not want to give me 50 free mp3 and just get 50 free downloads, use this link :
(http://www.emusic.com/)
Not all popular artists and tracks are on emusic, but some of them include Mogwai, Spoon, Plain White T's, The New Pornographers, Barenaked Ladies, Moby
If you have some other good music sources, please share.