It seems unlikely that when the Universe ended I was the only 'survivor', so I'd think that other 'people' (or other instances of whatever I am right now) have got to be out there. Is someone reading this? Unfortunately this Livejournal link seems to be one-way from my perspective; I'm not even sure it really exists.
Doubting my own existence seems kind of dumb, though, so I guess Descartes was on to something.