I heard of a nice little thought experiment which concerned the idea of artificial intelligence, can machines think, what is consciousness, etc, and also immortality of the mind.
So, how about, you get a small computer to take over the job of a set of neurons that are about to kick the bucket. You hook up your computer to all the little synapses that the old cells were talking to and you start the simulation. Can you tell the difference?
If not, repeat. Over many iterations, your brain should be completely replaced with computers, all without you even noticing so there is a continuity of consciousness. Now you are immortal (until the power cuts out). Your bits can be replaced indefinately.
Of course, it would be a pretty intellectual existance, unless someone can create an artificial twanger that can be plucked with as harmoniously as a natural one.