Remove heavy outer husks from corn; pull back inner husks. Remove and discard silks. Pull husks over corn. Cover corn with water; let stand 1 hour.
Stir together 1/2 cup softened butter, 1 tsp. grated lime rind, and 1 tsp. lime juice.
Drain corn, and pat dry.
Grill corn, without grill lid, over medium heat (300° to 350°) 25 minutes or until tender, turning often. Remove corn from grill. Carefully pull back husks, and tie with a leftover husk or kitchen string. Spread with desired amount of butter mixture. Sprinkle corn evenly with desired amount of chili powder.
Note: Stir 1/2 tsp. chili powder into the butter mixture, if desired.