U.S. Department of State Bureau of Consular Affairs - Subdivision of the Department of State whose mission is "... to protect the lives and interests of American citizens overseas and to strengthen U.S. border security." Site includes passport information, travel warnings, embassy registration information, and more.
Schengen Agreement - Information for U.S. travelers to Schengen agreement nations provided here.
TravelMath - Information on various logistic questions encountered in planning a trip, including timing, travel distances, airport information, and travel cost calculation.
