Copying the state of a brain, and recreating that state in a clone or a computer is theoretically possible. This kind of immortality will likely be only available for the rich at first.

As technology progresses, things become easier and cheaper to manufacture or perform. In the distant future self replicating molecular nanomachines will be able to manufacture anything and everything we want or need, even without the proper raw materials since they will be able to convert anything to the material they need through molecular and subatomic manipulation. This abundance will lead to currency being obsolete, and concepts of wealth and poverty may become meaningless; I suppose then all humans could gain access to immortality technology, but we might wipe ourselves out, or knock ourselves back to the stone age before we reach that point.

If everyone could have access to immortality, then strict reproduction limits would be required, as well as some colonies on new habitable planets.

lol this is just dumb.
you can copy your mind to a clone.
it dont make it you, its a copy that has your memorys.
who really cares if there is a copy of you around after you die.

Wait, what? Why would it do that?

I recently read book called "Old Man's War". In it they gave old folks the option of transferring their mind into a super soldier clone instead of eventual death. What they did was hook some kind of link between the clone and original brain so the consciousness existed between both bodies at the same time for a minute or so, then the original would be "shut down", leaving the clone.

This could be a solution to the whole "die every time you use your clone" thing, but it's pretty hard to imagine existing in two bodies as one mind.