WHO - World Health Organisation, information on diseases and vaccinations needed for most countries. Also up to date statistics on outbreaks and containment policies.
UNMAS - Website of the United Nations Mine Action Service, coordinating and facilitating the removal of land mines and other explosive remnants of war
UNOPS - United Nations Office for Project Services, handling infrastructure, vertical and horizontal contruction projects on behalf of sister UN agencies, Government bodies and NGOs
Lonely Planet - The same people who produce the ubiquitous travel guides. Good background information on visas and travel in countries off the trourist routes
Project Management Institute - Providing resources and benchmarks for professionals in the project management field
Engineering Toolbox - A great resource for field engineering and construction personnel. Includes a set of handy unit conversion tools to save counting sheep.
X Rates - Currency conversions and monitoring tools for expats who travel the world
UTM converter - A handy utility to get UTM GPS coordinates into Google Earth. We maintain this for legacy purposes now, Garmin desktop software can do this seamlessly
"Just because something doesn't do what you planned it to do doesn't mean it's useless"
-- Thomas A. Edison