Then: no, apparently you can't. Your notion of personal identity seems to be tied to a particular body and location, if I'm reading you right. Which also implies that your notion of personal identity can't survive death, and can't be simultaneously present on Earth and Mars.
Which of course does not preclude the possibility of someone on Mars, or existing after your death, who would pass all conceivable tests of being you as well as you would.
TheOtherDave, you seem to be implying that Locaha is unusual in not being able to experience Bill Gates's reality, and that in principle it should be possible to "identify with" Bill Gates and then suddenly "wake up" in Bill Gates's body with all of his memories and whatnot, thinking that you had always been Bill Gates and being none the wiser that you had just been experiencing a different body's reality a moment ago.
If that is possible, then how do we know that we aren't doing this all the time? Also, if this were possible, then we...
Scott Aaronson has a new 85 page essay up, titled "The Ghost in the Quantum Turing Machine". (Abstract here.) In Section 2.11 (Singulatarianism) he explicitly mentions Eliezer as an influence. But that's just a starting point, and he then moves in a direction that's very far from any kind of LW consensus. Among other things, he suggests that a crucial qualitative difference between a person and a digital upload is that the laws of physics prohibit making perfect copies of a person. Personally, I find the arguments completely unconvincing, but Aaronson is always thought-provoking and fun to read, and this is a good excuse to read about things like (I quote the abstract) "the No-Cloning Theorem, the measurement problem, decoherence, chaos, the arrow of time, the holographic principle, Newcomb's paradox, Boltzmann brains, algorithmic information theory, and the Common Prior Assumption". This is not just a shopping list of buzzwords, these are all important components of the author's main argument. It unfortunately still seems weak to me, but the time spent reading it is not wasted at all.