WHO - World Health Organisation, information on diseases and vaccinations needed for most countries. Also up to date statistics on outbreaks and containment policies.
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
"One of the tests of leadership is the ability to recognize a problem before it becomes an emergency"
-- Arnold H. Glasow