Soak ten 9-inch bamboo skewers in water for at least 30 minutes. Meanwhile, in a medium bowl, toss the steak with the olive oil, 2 teaspoons pepper and the salt. Let stand at room temperature for 15 minutes.
In another medium bowl, combine the pineapple, sugar and remaining 2 teaspoons pepper; toss to coat.
Thread 5 or 6 pieces of seasoned steak and pineapple alternately onto the skewers, and set on a plate or baking sheet. Season with salt.
Lightly coat a grill pan or large, heavy skillet with cooking spray and set over medium-high heat until very hot. Lower the heat slightly and, working in 2 or 3 batches, grill the skewers in the pan, turning once, until the pineapple and steak are golden, about 5 minutes. Let rest for 5 minutes before serving.