Lines are expected Saturday outside some medical marijuana dispensaries in Las Vegas and other Nevada cities that will begin selling pot for recreational use for the first time since voters approved it in November. Anyone who is 21 with a valid ID can buy up to an ounce of pot, one-eighth of an ounce of edibles or concentrates. State regulators have notified at least 17 retail outlets that they have been approved for recreational sales and as many as 40 could be licensed by Saturday. Some outlets plan grand opening events at 12:01 a.m., and one in Las Vegas is having a barbecue with raffle drawings. Industry experts predict Nevada's market will be the nation's biggest, at least until California plans to begin recreational sales in January. People have been allowed to use marijuana in private homes since Jan.