What's the difference between being an A.I. and being a human being? Listen to how one writer imagines the unimaginable:

She had been in her human body only a day, and yet already the electronic self that once had felt so copious was far too small... it was small by nature. The ambiguity of flesh made for a vastness of possibility that simply could not exist in a binary world. She had been alive, and so she knew now that her electronic dwellingplace gave her only a fraction of a life. However much she had accomplished during her millenia of life in the machine, it brough no satisfaction compared to even a few minutes in that body of flesh and blood (Orson Scott Card, Children of the Mind, p. 293).

The "She" here is Jane, an intelligent computer program (although that doesn't quite do her justice) who is one of the central characters in Card's Ender Quartet. In the fourth and last book, in a complicated series of events, Jane experiences an incarnation. The above episode describes her reaction to a temporary return to her former electronic existence.

What's interesting, perhaps, is that Jane is all along depicted as intelligent, as a person, as having emotions, friendships, etc. So while her existence as an A.I. is very different from our own, in some ways superior and in others inferior, still it seems right to regard her as "one of us," a member of the moral community, both before and after she inhabits a body.

Of course, this is a novel. But maybe it's interesting to think about...