+<li>Download <a href="http://files.kde.org/marble/downloads/maemo/fremantle/marble-desktopsummit_2011-08-02_armel.deb">marble-desktopsummit_2011-08-02_armel.deb</a> somewhere to your Nokia N900</li>. Don't open the link directly, the package is big (126 MB) and likely fills your root partition then.