USEFUL RESOURCES FOR TRAVELERS
This site is an absolute wealth of information on required and recommended vaccinations for travelling to all countries in the world. It also gives very helpful information on specific diseases and their symptoms, cures and prevention methods.
If you're interested in the month-to-month average temperatures of world cities this is the resource for you. From their site "This global web site presents OFFICIAL weather observations, weather forecasts and climatological information for selected cities supplied by National Meteorological & Hydrological Services (NMHSs) worldwide."
Gordon has a great collection of travel photo galleries on his site.