Sprinkle the rub on the ham cubes and thread them onto skewers. (If you're using wooden skewers, soak them in water ahead of time, so they won't burn on the grill.) You can thread the fruit between the ham, or put the fruit on separate skewers. Grill the skewers on a grill or on a grill pan just long enough to get grill marks on the meat and to warm it through. Serve warm.