You can use folders to organize the contents of your site, and the hierarchy you define using them will be reflected in your site map. As to the columns, there’s one way, but it won’t work with IE (they’ll still see one tall column). Try the CSS3 Columns Action, available at http://ActionsForge.com
Thank you, Walter. However, after reading the Softpress Knowledgebase article, I decided that I don’t need a sitemap after all as the navigation already allows visitors to get to any page from any page. Phew.