Ubuntu is nice and friendly, and supports the Debian package system, which we all know and love with the "apt-get" command to allow us to add and remove programs. Unfortunately, for historic reasons and lots of momentum to overcome, the folks at the Drupal project don't really see the pressing need to support apt-get. They are more in love with their new module "drush" which does some of the things necessary to make the code updateable.
To do things right, it's going to be necessary for some small group to get apt support build into things to the point that you can just apt-get drupal6 and actually get good results. As it currently stands, the initial results are encouraging, because it now actually does work, to get the install in place.
It's once you get there, you then have NO documentation as to what to do next. It doesn't ask you about what folder you want to put it into, it doesn't tell you how to proceed to setup... (hint: http://localhost/drupal6/install.php)
The worst part of it is that the version in the repository is about 5 releases old, and thus you leave yourself open to a huge set of vulnerabilities unless you then manually update things, which totally defeats the purpose of aptitude support.
So.. I'm going to try again, eventually I'll have something at http://cabsec.com, it might be a Google blog at the rate things are going, but there will be something there eventually.
If you use Drupal, you MUST be prepared to manually update it, the automation isn't there, and won't be for a while.