I have written a script called the Leonardo Image Functions Library, which is a library of image functions (obviously) that lets you do some pretty complex stuff with simple functions. This allows you to edit images easier than you would with the normal GD functions. Please check it out here.
Also, please give your feedback. You can find ways to contact me in my profile, or send me a mesage.
If you have ideas for the next version, please contact me. Currently, I am working on a beveling function and a gradient line function.
Download the code, examples, and documentation here.