I hear its pretty hot over at Instructables, this is the drink for you and the whole Instructables community. I hope you enjoy it.
Step 1: Ingredients
1/4 cup sugar
1 tablespoon lime juice
What I used:
Magic Bullet or Blender
Step 2: Dissolve Sugar
Step 3: Chill the Syrup (dissolved sugar and water)
Step 6: Add Syrup and Lime juice
Step 7: Pour into baking pan
Then put in the freezer to freeze.
Step 8: Scrape the Watermelon Ice
Finish with a little slice of watermelon with the rind (watermelon skin) still attached.