A simple hack that allow you to edit read only Google docs is explained here
http://googlesystem.blogspot.com/2009/01/copy-google-documents-to-your-account.html
It works and all you need is to hack the url a bit like this
http://docs.google.com/View?docid=AAAAA
to
http://docs.google.com/DocAction?action=copy&docid=AAAAA
where AAAAA is the doc id.
The site also provides a GreaseMonkey script to automate the process.
Its true that there is not need for such a hack as it can be done by simply copy pasting the html to the editor. But this hacks shows that Google docs which is still in beta, needs more work to patch these holes.