I came across this article which outlines the few steps necessary to upgrade the stock OpenOffice installation that comes with Kubuntu 8.10 to OpenOffice 3. http://news.softpedia.com/news/How-To-Install-OpenOffice-org-3-0-in-Ubuntu-8-10-96449.shtml
In order for it to run you must remove the package openoffice.org-kde, otherwise it will crash on startup. You can use the Synaptic Package Manager to find and remove that package.
Here's more information on the issue:http://ubuntuforums.org/showthread.php?p=6414782http://ubuntuforums.org/showthread.php?t=993516&highlight=untitled+crash+openoffice.org-kde&page=6
Unfortunately, all the mirrors no longer have the file they mention, so for now (1 Jan 2009) the only fix I know of is to remove the kde integration package. OO will look ugly but it seems to work.