One of my favourite blogs is the DigitalBuzz blog, it features lots of great not for profit and commercial marketing campaigns.
I saw this on on the site tonight, it's a collaboration between Amnesty and Shazam. I think the idea is just brilliant. A really good way to put your message in front of people who are typically hard to reach.
The blog on the DigitalBuzz site is here.
Update; for some reason the video has been taken off of YouTube. Will repost the link if I can find it somewhere else!