Correct way to change hostname?

Hi,

I was wondering what the correct way is to change the hostname/FQDN so that it reflects in the linode itself. I have a domain in Linode's DNS manager, but how can I get the linode to reflect this when I run hostname / hostname -f without modifying /etc/hostname, /etc/hosts, etc? Is this even possible? (running Ubuntu 10.04.1 LTS by the way)

Thanks in advance.