Bring a large pot of salted water to a boil. Add red potatoes, and cook until tender but still firm, about 15 min. Drain, cool and chop into 1" cubes. Place in a medium bowl.

Place eggs in a medium saucepan, and cover with cold water. Bring water to a boil, and immediately romove from heat. Cover, and let eggs stand in hot water for 10-12 min. Remove from hot water, cool, peel and dice.

In a small bowl, whisk together mayonnaise, milk, vinegar, green onions, salt and pepper. Pour the mixture over the potatoes, and mix together with the eggs and celery. Cover, and chill in the refrigerator approximately 2 hours before serving.