Split the cantaloupe in half and use a melon baller to scoop out the fruit. Place the fruit in a separate bowl. Slice the bananas and add them to the cut melon pieces. Wash the grapes and them add them to the rest of the fruit. Toss gently and then place back inside the cantaloupe halves.
* I found that the cantaloupe halves were a bit large for single servings. I trimmed an additional inch off of each half. I cut them almost triangular, three cuts, and that formed three slight points on the bowl.