Bezier curves and knots script for Blender

This is a Python script that I've been working on for Blender, to generate 3D geometry based on bezier curves. My goal is to produce a variety of attractive and accurate Celtic knots and braids to use as artistic elements in my projects.

I developed a customizable picture frame as a testbench for my work. You can use it as a stand-alone project to generate a picture frame with text (or without).
http://www.thingiverse.com/thing:54020

Adding Celtic knot elements to that, my Celtic Picture Frame is an early result of these experiments.
http://www.thingiverse.com/thing:55464

I have more ideas and enhancements that I hope to share later. The script is is in a usable state now, so give it a try!

UPDATE: 2012 Mar 6 -- version 1.1. uploaded to fix bugs in the utility function ReadCurveControls()