If you've ever wanted to define a path of points and then draw a smooth curve through those points (e.g. for rivers, roads, borders, etc), then I have created a GIMP plugin for you. The Smooth Path GIMP plugin takes the active path and smooths it according to a Bezier interpolation algorithm I will not bore you with here. Below is a screenshot to illustrate what I mean:
You have the option of preserving corners sharper than a specified angle. A preview of what these settings do can be found here.
Download the plugin from here or here.
Thanks to the legendary RobA for his valuable contributions to this plugin.