Cannabis plants that will soon be harvested grow at Northwest Patient Resource Center in Seattle, Washington January 27, 2012. Efforts to legalize marijuana for recreational use are gaining momentum in Washington state and Colorado, despite fierce opposition from the federal government and a decades-long cultural battle over America's most commonly used illicit drug. Photo taken January 27, 2012 REUTERS/Cliff DesPeaux (UNITED STATES - Tags: HEALTH SOCIETY)