I did these a little while ago in Processing but I love them. It’s just a grid of circles and splines that connect the centers at random. (These are Catmull-Rom splines, to be precise. They’re the same thing that I used for the projections in “Hello World.”) By clicking the arrow keys you can add more circles or more splines. If you want, you can download the Processing .PDE file here.
Fun with Splines