Opcion Font Viewer is a great little program, thanks guys
How to install a .jar file like Opcion_v1.1.1.jar and create a shortcut to it:
Download the file to your desktop from here: http://opcion.sourceforge.net/
Create a folder called "opcion" and put the file Opcion_v1.1.1.jar in it. Extract the file (right-click > 'Extract here') if you want to add an icon later, though it's not necessary.
Then move the folder to Ubuntu's programs folder, in terminal:
To create a shortcut (in Gnome, I am not sure how in 12.04 Unity): Right click on 'Applications' in upper left corner, select 'Edit menus' > 'Graphics' and click 'New Item'.
sudo mv ~/Desktop/opcion/ /usr/share/
Name: Opcion font viewer
Command: java -jar /usr/share/opcion/Opcion_v1.1.1.jar
If you extracted the folder, you can add an icon: Click on the trampolin icon to the left and navigate to /usr/share/opcion/Opcion_v1.1.1/FontViewer/resources/icons and select IconSmall.png