State of the world on drug decriminalization

Personal possession of any drug decriminalized: Spain, Portugal, Italy, Czech Republic, Baltic states, some German states and Swiss cantons, Mexico.

Partial decriminalization/minimal criminal prosecution: England, Denmark, Slovakia, Latvia, Croatia, Poland, Austria, Germany, France, Netherlands (see chart in the Economist story linked below--it's interesting that the Netherlands has the highest percentage of prison outcomes on this list)

Unconstitutional to prosecute people for drug possession (any drug) per Supreme Court ruling: Argentina, Colombia

Marijuana decriminalized: 14 U.S. states (Alaska, California, Colorado, Maine, Massachusetts, Minnesota, Mississippi, Nebraska, Nevada, New York, North Carolina, Ohio, Oregon)

States with some localities that have decriminalized marijuana: Arkansas, Illinois, Kansas, Michigan, Missouri, Montana, Washington, Wisconsin

Considering marijuana legalization: California, Massachusetts, possibly Oregon

Considering decriminalization (any drug): Brazil, Ecuador

Source: The Economist, "Virtually legal," November 14, 2009; state decriminalization details from Wikipedia.