Preheat half of the grill, setting the burners to high.
Tightly wrap the pineapple in two layers of aluminum foil. Place on the side of the grill that is off and close the lid. Cook for 1 hour or until tender, maintaining a temperature of 400°F (200°C) and turning halfway through the cooking time. Place on a plate and remove the foil.
Preheat the rest of the grill, setting the burners to high. Oil the grate and the banana.
Grill the pineapple and other fruit for 5 to 12 minutes, depending on their size, turning often. Make sure they are well marked. Place them on a large cutting board and let cool. Before serving, cut the fruit and glaze with syrup (see recipes at right), if desired.