WSU Library's list of links to websites that provide information on each country in the world, including the State Department's electronic Background Notes, the CIA World Factbook, etc.
The Fletcher School at Tufts University used to maintain a database of multilateral treaties worldwide. They stopped in 2009. This is an archived copy of the database.
A free commercial directory of all embassies of all countries. Search for all embassies within a given country, or all of the embassies of a given country.