Blender -- Origin Snap

This is a blender plug-in that lets you easily set the origin of an object relative to its' bounding box.

Sort of works for animated objects, buggy though!

Set Origin panel can be found in side toolbar:

Item > Origin-Snap

To install:

Edit > Preferences > Addons

Click the install button, select the origin-snap.zip, then click "Install Add-On"