I knew that I had seen this sometime somewhere when I was looking for it. Even my SharePoint buddy didn't know how to pull off this little trick. But thanks to Chan's post, I now have a link to the solution! :-) You can get the HTML to display contents of a Document Library or a List (just a list of items, no toolbars) by using the RPC protocol, the nice thing is that you can also use RPC by providing parameters in the URL. For example this URL
would display the contents of the Document Library. Cool trick and very nice in combination with a Page Viewer Web Part for example. More info and screenshots on Chan's blog. Thanks Chan!