I just finished my first real Flex Gumbo Application. It is a tool to change your Email or FTP password when working with a DirectAdmin Environment.
DirectAdmin gave me the tools to use and I have build the Flex Web Application for it.
You can see a working version here, but this is only working for my websites. So you will not be able to use it to change your own password.
At this moment I have a English and Dutch version. If you like to translate it for your site just let me know and I will give you the translation file.