2D Bones Animation?

Has anybody done a 2D Bones Animation module?
Ferminho did one, as did Haramanai a year ago. I also remember a BB version on BlitzCoder but can't find that either.

What would you use bones for in 2d?

To animate a 2D character using data input rather than more traditional frames of animation. It's also called 2D Character Rigging (I think).
This is a video from one of the links I posted.

<edit> For anybody who is interested I found Ferminho's showcase which has a pre-release exe.