Creating a WYSIWYG editor with Protoype and Scirptaculous

Hi,

In my little blog engine, display a sidebar that has the 10 latest
images I have uploaded, it’s a list formatted with its Textile html
equivalent.

So I’d like to make my little list draggable. That’s easy, but now the
problem is that when I drop an element, it should add the test where I
drop it without making an RJS call to my server, unfortunately I don’t
know how to do that.

Any guidance? Has someone already done that?

Before using TinyMCK of Teh I’d like to be able to understand a little
how it works under the hood, and then use TinyMCE and customize it to my
needs.

Thanks in advance.