Ubuntu Intrepid had been released imo too fast, they should have been waiting for OpenOffice.org 3.0 to be released and integrate it. Now Intrepid has only OOo 2.4 and Cannonical will not provide it in their main ressources.
The Ubuntu installation, which the OpenOffice community provides, is using /opt paths and is not integrated into the window managers application starters.
Developper of Ubuntu provide resources for OOo3 on Hardy, Intrepid and also Jaunty. You just need to add the following packages:
deb http://ppa.launchpad.net/openoffice-pkgs/ubuntu intrepid main
deb-src http://ppa.launchpad.net/openoffice-pkgs/ubuntu intrepid main
Of course, select the appropriate distribution on the packet source. I will try this to get OOo3 for our diskless Hardy clients. Sources: 1 2