Remove stems from strawberries to form a flat base. Place strawberries on cutting surface, pointed end up. With sharp knife, carefully slice each strawberry in half vertically to within 1/4 inch of base. Cut each half into 3 wedges to form 6 petals. (Do not slice through base). Pull petals apart slightly.
In small bowl, beat cream cheese, powdered sugar and sour cream until light and fluffy. With pastry bag and star tip or small spoon, fill strawberries with cream cheese mixture.