Where can I download pretty extra templates for LibreOffice Impress?
You can also install this package (at least on Ubuntu): libreoffice-templates - Additional set of templates for LibreOffice.
Download “Modern Impress Templates” extension and install it through Extension Manager.
http://extensions.services.openoffice.org/node/1338
You can also use something from IBM’s repository.
http://www-03.ibm.com/software/lotus/symphony/gallery.nsf/GalleryPresentations?OpenView&Count=15