Is there a GUI for /etc/hosts that I can use?

As already answered hosts is just a text file so you can use any text editor. Since it exists in /etc and you cannot edit as general user you need to use sudo. The graphical frontend to sudo is gksu. So basically doing gksu YOUR_GRAPHICAL_EDITOR /etc/hosts will do it OR you can use terminal with nano and vim. I recommend nano as it is quite easy.

sudo nano /etc/hosts

In order to ease the command you can use alias.

So edit your .bashrc file in your $HOME. i.e. In your terminal do:

nano .bashrc 

Add

alias edithosts='gksu YOUR_GRAPHICAL_EDITOR /etc/hosts' OR 'sudo nano/vim/vi /etc/hosts'

and save it with Ctrl+x. And do source ~/.bashrc. Then you can use edithosts from commandline to use it.

If you use unity you may use quicklist as well What Custom Launchers and Unity Quicklists are available?

sagarchalise's answer is great, I also discovered gnome-network-admin which includes a pretty nice interface to edit hosts

sudo apt install gnome-network-admin

It's not a special editor as such, but you could always Alt+F2 gksudo gedit /etc/hosts.