It is always a good idea to have a few passports photos with you. You never know when you will need them.
Leave a copy of your itinerary and a photocopy of your passport at home or with your family, to let them know your travel plan. It would be better, if the hotels you are going to stay are also known.
One of the best ways to stay in contact with the people at home, while you are traveling, is to have a web based email. Something like hotmail or avasmail. If you do not have a web based email account, you can setup an email account for free from these two sites.
If you loose your passport while abroad, do not start making unnecessary calls home. As this mishap could prolong your stay and you need to save as much as you can. Follow the steps below:
IF YOU ARE IN SRI LANKA, INDIA OR UNITED KINGDOM, CONTACT THE DIPLOMATIC MISSION