Whether you prefer OpenOffice.org or LibreOffice, which currently still are pretty similar, out of the box, they are missing some of the conveniences installed by their commercial counterparts. Granted, they are fully functional, but if you want a robust clip-art library and a decent selection of document templates, you'll want to add some extensions and templates.

Browse on over to extensions.services.openoffice.org and templates.services.openoffice.org to pick up some add-ons that will make your office suite shine. Whether you want to add a few graphics to your document or spice up your next presentation, the options are extensive.

Also, if your user has write access to the system files, you'll get the option to install extensions for all users or just the current user—an awesome boon for sysadmins like myself!