to install libreoffice in Ubuntu 10.04 you need to type:
sudo add-apt-repository ppa:libreoffice/ppa
sudo apt-get update
sudo apt-get install libreoffice libreoffice-core libreoffice-base libreoffice-filter-mobiledev \
libreoffice-java-common libreoffice-common libreoffice-gnome
if you also want the gui in your language install
sudo apt-get install libreoffice-l10n-de
(replace de with your language code)
Update: this works with Ubuntu 10.10 Maverick, too.