Peaches and pineapples are both delicious when grilled.
The pineapple should be sliced and cored and then you can add whatever spices you want! You can even grill them plain and enjoy them as an accompaniment to chicken or pork or fish. They are also good on skewers. I find a sprinkle of chili powder or curry is delectable.
Peaches can be halved or sliced and put on skewers. You can try them plain or with honey and garam masala. Some people enjoy them with a pinch of sanaam chili powder or chili flakes to balance the sweetness of the fruit.