Jamendo supports posting reviews/widgets/.. to blogs. This page lists which are compatible with this feature.

Blogger.com

• status* : supported very soon, we're still working on it

Facebook.com

• status* : OK
• formats* : on the Wall, text and valids urls only (http://...)

MySpace.com

• status* : OK
• formats* : limited html ("iframe" tag unsupported)

Over-blog.com

• status* : OK
• formats* : html

Skyblog.com / Skyrock.com

• status* : OK
• formats* : BBcode, text

Wordpress.com / Any WordPress blog

• status* : OK
• formats* : html
• misc* : post may not show up immediately on wordpress.com