Could I change sudo nano /etc/hosts?

Sure, if you know what you're doing. Don't delete any of the existing entries, just add whatever additional hosts you want to define.

Just to clear one thing up - the filename is /etc/hosts, the text editor you're using to edit it is called "nano", and you're adding "sudo" to give yourself superuser privileges. So the whole command is indeed "sudo nano /etc/hosts", but you're adding lines to the hosts file.

Matt

I urge you very strongly not to modify the hosts file. What are you trying to accomplish?