Maori
When Rob gave his presentation about New Zealand at camp, he demonstrated the traditional Maori greeting with a camper.
Both participants touch noses. The younger person exhales through the nose, and the elder inhales. Then the elder exhales through the nose and the younger in turn inhales. In doing so, the younger party extends his vitality to the elder and then the elder in turn extends wisdom to the younger.
Thus, it is a great honor in Maori custom to greet elders.