in one of Carloss Castaneda books (don't remember which) it is told about a man who had lived already a thousands of years. he was born in ancient atlantis or some kind of ancient land. he was taking anergy from other people in order to survive and he was giving them Knowledge in return.
he was even bored with beeing a man eventually and with the help of his megical powers turend his sex from male to female.

Well, I don't know about immortality, but I do think there are certains things like modification of DNA, that could make one live far past the expiration date. I saw this program a few months back, and it discussed the possibilities of altering humans to let them survive and even have children on a journey into space that would last generations. They also figured that the astronauts would have to get way older then a normal human being. Then they told about an experiment in which they eliminated the age genes of a worm, and it lived more then 5 times longer then it normally would. Atleast that raises hope in our search to a way to stop our aging.

In my oppinion, immortality is similiar to infinity, and that's something we can't comprehend. Every single thing that we know, dies or ends at one point. In the world that we live in, and the knowledge we possess, there is no immortality.

There can be only one.