Preheat your barbecue or indoor grill to medium. Place the melted butter and curry powder in a small bowl. Brush some of the mixture on each cob of corn. Place the corn on the grill. Cook the corn, turning from time to time, until lightly charred and just tender, about 5 minutes. Set the corn in individual serving plates or on a platter and garnish with lime slices. Let diners slather the corn with soft butter, and sprinkle with salt, to taste.