Thanks for your replies. I am also looking into Tibetan Buddhism. Just read "How to Practice" by The Dalai Lama last night. Found it quite fascinating. It appears that Tibetan Buddhism is similar to Mahayana Buddhism in the belief that one can become enlightened in this lifetime. They emphasize the mantra: OM MANE PADME HUM, which is loosely translated as the jewel in the center of the lotus. Here's another interesting website:
http://dharma-haven.org/tibetan/meaning-of-om-mani-padme-hung.htm

Peace,

Robert