QUOTE(annatenna @ Jul 6 2008, 03:57 PM)

I was asked for my passport at the interview. The interviewer used it mainly to check that the dates I'd been out of the USA were accurate, by comparing the dates I'd given in N400 with the date stamps in the passport.
Perhaps you should obtain a replacement passport as soon as possible- unless you haven't spent any time out of the USA at all, I think there's a good chance they'll need to see one, but even if you haven't been out of the country they might still want to confirm that from your passport also.
thank you