I recently released a fractal program with a new interface for working with iterated function systems. It redraws the fractal in real time as you visually manipulate the parameters of the IFS. It's called "TeraFractal", a play on "pteradactyl" (the dinosaur). The software is free and available for Mac OS X 10.3.9 and above (universal binary).
For more information and to download, go to
http://www.robinstewart.com/products/terafractal/Here is an example fractal that is easy to make with TeraFractal:
If you create more cool fractals using TeraFractal, email the files to me and indicate if you would be willing to let me include them in the standard distribution.
-Robin Stewart