Place the potatoes in a large saucepan and cover with water. Bring to a boil. Reduce heat and simmer, covered, 10-12 minutes, or until potatoes are tender.
In a food processor, combine the cream cheese, salmon, onion, dill, lemon juice, salt and pepper. Cover and process until smooth; set aside.
Drain potatoes and immediately place in ice water. Drain and pat dry with paper towels. Cut a thin slice off the bottom of each potato to allow it to sit flat and cut in half. With a melon baller, scoop out a small amount of potato, allowing room for mixture.
Pipe or spoon salmon mixture into potatoes. Garnish with dill sprigs.