While watching a news program back when I was in Boston last March 2008, there was a story that flashed about a student left alone in Italy because she lost her passport in the back of a taxi cab. While it was a shocker to know that the accompanying teacher just gave money to the student to go to the embassy and left her in a foreign country by herself, what stuck on my mind was the moral of the story - research about the policies of the place you're heading too before taking off and anticipate unfortunate circumstances. Because the teacher was unaware of such policies, the student missed her flight although she could have come home with the others in the group using a photocopy of her passport.
So as a travel tip, always keep additional copies of your passport aside from the original - in your purse, handbag or backpack, in your luggage, and if possible, upload a digital copy in your email inbox or a somewhere secured over the internet. You may also include information of the nearest embassy or foreign affairs attachment where you are visiting. You never know when all these may come in handy!