During the weekend, I decided to upgrade the server running my blog from Ubuntu Server 7.04 to 8.04 since version 8.04 is an LTS and is supported through 2013.
Instead of performing upgrade directly on the server, I decided to install everything from scratch. In order to ensure minimum downtime, I created a VM first and installed the latest Ubuntu Server 8.0.4.1 there. After everything worked, I directed my production url to the VM server while working on the installation on the physical server. This way, the downtime is minimized to just a few minutes (the time required to redirect web traffic).
Ubuntu Server 8.04 has made server setup easier than before. Some common configurations (e.g. LAMP, SSH Server, Print Server) can be selected during installation, which makes post-installation configuration trivial.