Wow. I never even knew about this company, called Humanize. But Mozilla just hired 3 of the main guys . I just checked out Songza  and it's got a very simple, very cool interface. Not to mention that it lets you just listen to music. The interface is so simple, so clean, I immediately started using it.
It's always fun to learn about cool companies who are making great products. Specifically I google aza raskin and found his wikipedia page, which linked to a very good article "never use a warning when you mean undo" .
 - http://www.techcrunch.com/2008/01/15/breaking-mozilla-buying-humanized/
 - http://www.songza.com/
 - http://www.alistapart.com/articles/neveruseawarning