Portugal decriminalised the use of all drugs in 2001. Weed, cocaine, heroin, you name it Portugal decided to treat possession and use of small quantities of these drugs as a public health issue, not a criminal one. The drugs were still illegal, of course. But now getting caught with them meant a small fine and maybe a referral to a treatment program not jail time and a criminal record.
This is exactly what the rest of the world needs to realize. Use the money you would spend locking up people from drug possession on rehabilitation and education. I think they should go one step further and regulate drugs all together.