In large bowl, mix hamburger, rice, 1/2 cup water, onion, salt, garlic powder and pepper. Shape into about 24 1-1/2-inch meatballs. Cook meatballs in skillet until browned on all sides. Drain off extra grease.
In small bowl, mix together tomato soup, spicy V-8 juice, Worcestershire sauce and red pepper flakes, if using. Pour over meatballs, turning meatballs to coat. Cover and let simmer for 45 minutes.
Notes
Depending on the type of skillet you use and the temperature of your stove (my stove runs hot so I simmer on the lowest possible setting), you may need to add additional liquid while simmering. If so, stir in a little V-8 juice as needed.If you don't have V-8 juice on hand, you can use two cans of tomato soup instead. When I do this, I add some Italian seasoning for added flavor.