If you really want to live for ever - or at least have a better shot at it than we do now - you'll need to be frozen. See Alcor.

Right now, freezing does a lot of damage to your body's cells, but methods of vitrifying tissue (freezing so that ice crystals are not formed) are being aggressively researched for use on transplant organs. When that becomes possible, you'll be able to be frozen with no cellular damage.

There are so many things that seem to contribute to aging it's hard to see any light at the end of the tunnel. Hear are a couple:

1. deterioration of telomeres - every time a cell divides, the repeating nucleotide sequence that protects the coding regions of chromosomes lose a few of the repeats. Once the telomeres drop below a certain length, they stop dividing. Many cancers turn on the telomerase gene to compensate for the loss. Other cancer cells continue to divide in spite of it.

2. oxidative damage - highly reactive chemicals that are the by-products of normal cell respiration.

3. accumulated dna mutations due to anything from toxins to cosmic rays.