If you are older you should definitely be focusing on strategies for biological life extension (calorie restriction, or whatever), and everyone should sign up for cryonics as an insurance policy.
Ultimately, with full molecular nanotechnology, whether the engineering of negligible senescence is biological or digital is rather beside the point ("What exactly do you mean by ‘machine’, such that humans are not machines?" - Eliezer Yudkowsky).
However, Unfriendly AI would render the whole point moot. So the most important thing is to guarantee we get Friendly AI right.
If you have a sufficiently high probability estimate of either FAI or UFAI arriving before your natural death.
What looks, at the moment, as the most feasible technology that can grant us immortality (e.g., mind uploading, cryonics)?
I posed this question to a fellow transhumanist and he argued that cryonics is the answer, but I failed to grasp his explanation. Besides, I am still struggling to learn the basics of science and transhumanism, so it would be great if you could shed some light on my question.