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
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
"Reason and judgment are the qualities of a leader"
-- Tacitus