Start with about 6-8 slices of the pre-sliced ham. Slice into 1" wide strips until you have 20 thin ham strips; slice up more ham if needed. Set aside.
Using a melon baller, scoop out 20 round cantaloupe bites and set aside on a plate.
Take one skewer and slide one mozzarella ball onto the skewer. Then, fold a 1" slice of ham into a nice neat little rectangle and slide through skewer. Slide a cantaloupe ball through the skewer. Sprinkle some basil over the mozzarella.
Repeat until you have finished about 20 skewers.
Drizzle balsamic vinegar over the ham, melon, mozzarella bites.
Refrigerate until you are ready to serve.
