You can also use Javascript/DHTML to get this kind of feature.
Check out manila.userland.com and radio.userland.com.
It has an "Edit this Page" button that shows up when an editor is logged in. It also has a Edit with Radio button if you have it setup to use the desktop editor. It uses XML-RPC to communicate with your desktop machine.
I plan on building the external XML-RPC interface into the CMS, or as an optional module when the CMS is finished. The browser-based editor should be built right in. It should be possible to extend other products such as Word and Dreamweaver to talk XML-RPC also.
The browser-based editor is also used for discussion group posting editing for Manila web sites. It's pretty interesting.
