The best way to get rid of both slugs and snails is to sink a shallow bowl into the dirt and pour in some beer. An inch will do. They come from all around, climb in, and die happy in that beer. I would put bowls about 2 yards apart if you're doing a whole area. You can leave the bowls out for a couple of days--they don't care if the beer is flat (and that way you're not wasting any more beer on them than absolutely necessary!)

SRS