LVM (Logical Volume Manager) is a great piece of software which allow you to deal with Logical Volumes. Using LVM along with ext3 filesystem, you are allowed to extend the size of your logical drives which is pretty handy when running out of space.
Distributions like Fedora, Suse and Debian have a LVM aware installer. Unfortunately, at the time this article was written, Ubuntu does not offer such settings with the Desktop Install CD.
This article will cover how to create LVM partitions and how-to generate your partitions from this LVM volume.