From http://www.rtk-cv.dk/projects/umbraco-cms.aspx you can download a foldout menu
1. Copy tree.js into your root dir
2. Copy minus.gif and plus.gif into /images/
3. Go to Umbraco developer section and create a macro and xslt node.
4. Paste in the Menu.xslt code into your new xslt node
5. Insert the macro in your template and it should work
end of readme
Also to inlcude the tree.js file to your <header>. and at last add a doc.gif file to images