George Dvorsky (Sentient Developments) poses essential questions about the slippery status of "personhood" and suggests some useful philosophical strategies:
What is a person?
Looking to the future, and as we move forward with NBIC technologies, we run the risk of denying essential basic liberties to intelligent and sentient beings should we fail to better elucidate what it means to be a person (whether they be non-human animals or artificially intelligent agents). As Glenn notes, we need to be prepared to ask, "How can we preserve our human rights and dignity despite the fact that our 'humanness' may no longer be the exclusive possession of Homo sapiens?"
Although Dvorksy is addressing animals, humans and posthuman intelligences, it's worth adding that his criteria will almost invariably discover further validity in the event that we establish contact with extraterrestrials.