The Dalai Lama is the Physical manifestation of the Diety Avaloketeshvara (or the Buddha of Compassion): Om Mani Padme Hum invokes this Buddha of compassion as a mantra

Often while I was traveling in Nepal and northern India in the Himalayas in 1985 and 1986 people were wearing a silver bracelet with the script (usually in either Tibetan or Sanskrit of "OM Mani Padme Hum). It was very common then and might still be today. Sherpa Guides might either have this bracelet on or wear prayer beads while they out loud or in their head did this mantra for protection while helping climbers climb peaks throughout the Himalayas including Mt. Everest.