Preheat grill for direct-heat grilling.
Sprinkle cut sides of peaches with ground ginger. Brush with 1 Tb. melted butter.
Grill, cut sides down, until just tender, 2-3 minutes. Remove from grill. Slice and reserve.
With mixer on medium speed beat cream cheese, sugar, 2 Tbs. peach preserves and vanilla until blended and creamy.
Fold in zest and whipped topping until combined; reserve.
In small bowl combine graham cracker crumbs and remaining 2 Tbs. melted butter.
To assemble parfaits: layer each serving glass with 1/4 cup cheesecake mousse mixture, 1/4 cup graham crumb mixture, 1/4 cup cheesecake mousse mixture and 1 Tbs. peach preserves. Using bottom of a spoon, gently swirl preserves into top of cheesecake mixture.
Garnish with sliced grilled peaches.