In this post I posted pictures of some of my "inflationary notes". I now have notes from three of the greatest hyperinflationary periods of the 20th Century.
Weimar Germany, 1923:
click to enlarge
The first note is a 1000 Mark note counterstamped to be worth 1 billion Marks. It was cheaper and faster to release counterstamped notes than to produce new notes. But they still produced new notes, and the second one is 5 billion Marks. It's printed only on one side. Wikipedia has details on the rate of inflation, which peaked at around 29,500% in one month.
Hungary, 1946, and Zimbabwe, 2008:
Wikipedia has details on the rate of inflation, which peaked between 13 and 42 trillion percent in one month. Hungary in 1946 still holds the Guiness Book record for highest inflation rate of all time.
Zimbabwe's is the most recent hyperinflation, taking place not even a decade ago. Wikipedia has some details on the rate of inflation, but figures vary so much that it's hard to know which to trust.
A compilation of hyperinflation rates is available here.