Isn't the issue less what you ask the oracle, and more how you can be sure that in order to answer the question the oracle (or whatever it self-modifies into) won't turn you and the rest of the planet into computronium? As such, it seems that the only questions you could safely ask an oracle would be ones that you are sure are computationally tractable, or that you are sure the oracle could easily prove to be unsolvable.
The Future of Humanity Institute wants to pick the brains of the less wrongers :-)
Do you have suggestions for safe questions to ask an Oracle? Interpret the question as narrowly or broadly as you want; new or unusual ideas especially welcome.