Once upon a time, there was a prisoner in solitary confinement, a former public enemy number one of France, aside the wards alone in the prison and allowed only to read science books. When he came across an astronomy textbook by Lagrange, he suddenly had the same idea as you express. http://ideafoundlings.blogspot.com/2009/10/nemo-eternal-returning.html
Once I see the possibility that some idea may be expressed in crisp mathematics, I'm no longer interested in vague philosophical treatments of that idea.
We haven't discussed it here yet, have we? Article from August 2010. ArXiv link. The upshot:
The notion that I am this huge equivalence class of almost-identical human beings (just similar enough to be running the same mind-computation at this moment), scattered over a spatially infinite universe, sounds very UDT-ish. Unfortunately I don't know enough physics to judge the paper properly. Please halp.