He doesn't really play with the multiple-copies-of-one-person interacting though, from recollection. The Stone Canal touches on it, but Accelerando thinks a lot more about the interesting possibilities of what Stross calls "Multiplicity", where folk can freely fork many instances of themselves and potentially join the mind states up again later, etc. Revelation Space cheated its way around thinking about the issue by having alpha-levels be copy-protected. Altered Carbon has it be a rare and brief thing for anyone to be running in more than one place at once. I can see why they did this, but Stross' stuff is more interesting because he didn't shy away from that. I feel like this should be right up Peter Watts' alley, but I don't think he's written anything on this (yet). Uploads not plausible enough for him, I guess.

For other works that you may or may not be familiar with... Lena (or MMAcevedo, which seems like a better title) is a nice short online work that does a better job. Soma is a computer game (in the "walking simulator" style) that also has some great moments, though the protagonist is annoyingly oblivious.