Rachel has sent in four samplers recently. The first is another in Urban Outfitters' LSTN series (#10 for those keeping count). You'll get 25 songs for free (see link for full details).
People Magazine has an update to their recurring Country playlist with 11 country songs. While Lollapalooza is promoting their upcoming concert in Chicago with 10 free downloads.
Finally, you can get 23 free songs from the 2010 Latin Alternative Music Conference. Whew, that's a lot of free songs, thanks Rachel!