I photocopied the page in our passports with the details and photos on then laminated it. We could then lock the passports in the safe and carry the copies around with us. Don't know if it was because it was laminated and looked official but when we were asked for ID when changing $100 TC's it was always accepted as ID. It would also come in handy if we did happen to lose our passports as it has got the passport No's etc.