Response to a request: [Collision detection in bone physics](http://www.blendswap.com/requests/view/704).

Rigged using rigid bodies and empties. Can be used to rig ropes, cables etc. [Video](https://www.youtube.com/watch?v=f_Ct6SvPr_s) of usage example.

+ To help you easily set the rig up into some initial position, I built a simple IK rig, which can be found on the first layer.
+ If you want to freeze one or both ends of the rig, set the end rigid bodies' type to *passive*
+ If you want *pin* one or both ends to a bone/object, set the end rigid bodies' type to *passive*, check *animated* and *parent them* to a bone/object of your choice.