I read today on the Red Sweater blog that Suite Modeler is now free.
""" Don Briggs has announced that his highly-acclaimed Suite Modeler application is now free. I haven’t used it but many people suggest it greatly reduces the pain of adding scripting support to Cocoa applications. http://www.red-sweater.com/blog/links/89/suite-modeler-now-free """
I thought it might interest you (and maybe the rest of the list).
Suite Modeler http://homepage.mac.com/donbriggs/