This article specifically relates to the Linux version of Gizmo5. There are similar articles for Windows and Mac.
Adding a new Gizmo5 contact is a click away.
From within your Gizmo5 client just click the 
button at the bottom of your Gizmo5 phone.
You can enter just the Gizmo Project ID of the person you would like to add, or you can fill out the contact information by hand.
Once you've added your friend in, they will be viewable in your Gizmo Project phonebook, both online and in your Gizmo Project software.
