Jamendo supports posting reviews/widgets/.. to blogs. This page lists which are compatible with this feature.
Blogger.com
Facebook.com
- status* : OK
- formats* : text (in the Wall)
MySpace.com
- status* : OK
- formats* : limited html
Over-blog.com
Skyblog.com / Skyrock.com
- status* : OK
- formats* : bbcode, text
Wordpress.com / Any WordPress blog