Leave a detailed itinerary and the number of your passport or other citizenship documents with a friend or relative in the United States.

Carry your photo identification and the name of a person to contact with you in the event of serious illness or other emergency.

Keep photocopies of your passport, visa, airline or other tickets and a list of your traveler’s checks with you in a separate location from the originals and leave copies with someone at home.

Leave things like unnecessary credit cards and expensive jewelry at home.

Use a money belt or concealed pouch for your passport, cash and other valuables.

While in Russia and in many countries, you may be asked to turn over your passport to hotel personnel or a tour leader for short periods of time for registration with police or for other purposes. Your passport should be returned within two or three days. However, for U.S. citizens on long-term business or studies, the registration process can often take longer. It is not unusual for sponsors and local authorities to hold on to American passports for as much as several weeks while visas are registered or while exit visas are processed. Be sure to safeguard your passport at all other times, as its loss can cause you delays and problems.

If your passport is lost or stolen, you must apply for a replacement passport at a U.S. embassy or consulate. If possible, bring with you:

• identification, especially photo ID
• proof of U.S. citizenship (a birth certificate, naturalization certificate, Report of Birth Abroad or a copy of your passport)
• two 2" by 2" passport size photos, in color or black and white, and
• the police report that you filed when you notified the local authorities that your passport was lost or stolen.
  In most cases, a new passport can be issued quickly. If U.S. passport records must be checked, the process may delay the issuance of a new passport.

In Russia you must also obtain a new or duplicate visa from OVIR (Office of Visas and Registration) if your visa is lost or stolen. (This office is also known as the "Passport-Visa Service" in some areas.) The passport number on your visa must match that of any new passport. Obtaining a replacement visa takes approximately 10 working days. A police certificate verifying the theft of your visa and passport may be necessary to obtain a new visa.

The State Department's Tips for Travellers to Russia http://travel.state.gov/travel/tips/regional/regional_1176.html