The world's highest denomination note is Hungary 100 Million B-Pengo, issued in 1946. That's 100,000,000,000,000,000,000 Pengo. It was worth about U.S. $0.20 in 1946. Hungary also printed a 1 Milliard B-Pengo (1,000,000,000,000,000,000,000 Pengo) note in 1946. Overtaken by inflation, it was never issued. 
The lowest denomination note is Fiji 1 penny, issued in 1942. The old penny, being 1/240th of a pound, is a lower denomination than the current penny which is 1/100th of a pound. 
The note with the most zeros is a Yugoslavia 500,000,000,000 Dinar, issued in 1993 with 11 zeros. 
The note with no denomination - Tatarstan issued a series of currency checks without any denomination printed. 
The world's oldest surviving bank note is China Ming Dynasty 1 Kuan, issued 1368-99. Measuring 222mm x 340mm, it is also the world's largest bank note.
The smallest bank note in the world is Romania 10 Bani, issued in 1917. This postage stamp size note measured only 34mm x 45mm. 
The perfect forgeries, code named Operation Bernhard - Bank of England Pound notes produced by prisoners of war in a German Concentration camp. Circulated along with genuine notes.
The following countries have issued polymer plastic notes: Australia, Bangladesh, Brazil, Brunei, China/Peoples Republic, China/Taiwan, Costa Rica, Haiti, Indonesia, North Ireland, Isle of Man, Kuwait, Malaysia, New Zealand, Papua New Guinea, Romania, Singapore, Sri Lanka, Thailand and Western Samoa.
On January 1, 2002 Euro will become the official currency, replacing the national currencies, for the following 12 member states: Austria, Belgium, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, Netherlands, Portugal, Spain.
The four current monetary authorities which issue common notes for member countries are:
- Central African States - Cameroon, Central African Republic, Chad, Congo, Equatorial Guinea and Gabon.
- East Caribbean States - Antigue, Anguilla, Dominica, Grenada, Monserrat, St. Kitts, St. Lucia and St. Vincent.
- French Pacific Territories - French Polynesia and New Caledonia.
- West African States - Benin, Burkina Faso, Guinea-Bissau, Ivory Coast, Mali, Niger, Senegal and Togo.
The motto IN GOD WE TRUST first appeared on the U.S. $1 bill in 1957.
The highest denomination ever issued by the U.S. Federal Reserve Bank is $100,000. It was used only for transactions between the Federal Reserve and the Treasury Department.