Physical immortality is a common goal of many futurists and transhumanists, for that reason I've written a list of probable ways for one to live at least a very long time.
1. Anti-aging midication: The use of advanced medicine to stave off the effects of aging by rejuvenating mitochondria and lengthening telomeres, as well as reducing wrinkles and holding senility at bay. Would involve the least changes of any of the techniques on this list, but would not be viable over the long term as there are many different effects of aging and the human brain only has enough memory for a couple centuries of experiences at most. Also, it's likely that someone using this form of longevity would require organ transplants every few years.
2. Genetic immortality: Using genetic engineering to design a person born with the effects of anti-aging drugs, unfortunately this is unlikely to happen any time soon and would require a near complete re-design of the human body. In addition making an already fully-developed person immortal this way would require highly advanced nanotechnology, which brings us to the next option.
3. Rejuvenation: Periodically using stem cells and/or nanomachines to repair damage caused by aging and "reset" one's cellular clocks and effectively make them decades younger. May also include memory alteration, one could selectively "delete" certain memories in order to make room for new ones and only keep particularly notable ones.
4. Cyborgization: This method could range from simply hosting permanent nanomachine symbiont's to continuously repair and rejuvenate the body, to replacing almost all of one's biological body with mechanical parts. Machines are noticeably easier to repair than biological systems, and can also increase the amount of physical memory available to a person, eventually as even the brain is replaced this could cross over into Uploading.
5. Mind Uploading: In this option, as I stated in my August 17th post, the data contained in a person's brain is copied onto a different substrate. This does pose some existential problems but if you do accept that the copy is the same person as the original then uploading is the best way to achieve immortality. The other options don't make the person immune to accidents or murder, while a backup copy could be easily made as insurance against those situations. Heck, one could have an implant in their head that could transmit their consciousness to a cloning facility at the exact moment of death and be downloaded into a new body.