This is somewhat like how the 'Ndoli Device' works in some of the short stories of Greg Bear. (I'd especially recommend the story 'Learning To Be Me'.)
Ah, yes, of course... 'Learning To Be Me' is Egan's story, and the 'Ndoli Device' or 'Ndoli Jewel' appears in some of Egan's other stories as well. (I vaguely recall seeing the same term used elsewhere, maybe a Bear book, and thought it might be a specific allusion back to either Egan or some other common precursor.)
