I'd like the ability to make opium to smoke from poppy seeds. As you can do with some strains of poppy in real life, it could be used as a pain-killer to aid in the healing of certain wounds. Perhapes aid in the healing of bruises and blunt force wounds, a bit unrealistic but makes more sense than say, putting a bandage on a bruise.
That and we need more things to get stoned off of. Maybe it could also give you some damage resistance, or boosted con?
basically I just want an excuse to charge into battle smoking my pipe full of drugs.