Updates, I have a couple of things that I've been working on recently.
First there is a amalgamated circle generating and circlewriting lua script.
It can do things like this:
And this is a little more complicated (obviously you can get whatever colors you want for rings and text I was just feeling monochrome when I made these.)
The intertwining effect is made by making different bits of the circle at different points in the lua script. In lua the later instances of cairo graphics are drawn above any earlier instances.
The script can be found here on the crunchbang Linux forum (where you can see a more colorful use of the script. It can also generate bars that can be placed and rotated freely.