A little while ago I took the task suggested by dynamical.biz to implement a plugin for FCKeditor that would allow any end user to easily create a Google Map that can be inserted in the content and so it will be shown in the final page as he wanted.
But if I'm writing this post is because of course it did work, so you can test it online
Go, download it and play with it. For developers its code might have very interesting surprises, I'm not saying that the code is perfect, but I think that it does open the doors to make other plugins and code that previously were thought as "too difficult" (for example handling Flash files with the SWFObject, or being able to show at least a simple textarea to edit comments of PHP code). If you read this code (sorry if there aren't enough comments or everything is a little mixed up for the moment), you might find the bits that you need. And if you find this code useful, please contribute back your own ideas, plugins or why not?, a little donation