/etc/hostconfiggoes away, while System Preferences in the Sharing tab does not sets hostname as hostname. Thus all older recipes are not really applicable anymore, once you're on Snow Leopard (I love changes). The cure is how to setup your hostname to, e.g. "Zeus" (that's mine one) like this (terminal and sudo privileges are required):
sudo scutil --set ComputerName zeusThat's it (no reboot really required).
sudo scutil --set HostName zeus
sudo scutil --set LocalHostName zeus