Tribal Wall is an invitation only social network that allows members to interact with each other by creating and joining tribes. Each tribe has it's own wall where members can add posts and view tribe specific information. You can only join Tribal Wall if you received an invitation from a Tribal Leader. If you know a Tribal Leader, you can ask them to send you an invitation to join their tribe. You can also request an invitation to join a tribe by going to Tribes and clicking on the Request Invitation button.