Ubuntu Hardy Heron (8.04)
Ubuntu's next LTS release date is not scheduled until April of 2008. However, you can test drive what the future will look like today. Follow these simple steps to upgrade your existing Gutsy Gibbon installation to Hardy Heron! I always run what is known as "ubuntu+1" immediately after the first Alpha release is finalized, which occurred today. I am happy to say that the dist-upgrade went smoothly and all is well :-)
$ sudo sed -i "s/gutsy/hardy/g" /etc/apt/sources.list
$ sudo aptitude update
$ sudo aptitude dist-upgrade
All done! If you run into any issues, join the #ubuntu+1 channel on Freenode's IRC server...