Using a peeler, create stripes on the outside of the cucumber by peeling along length of cucumber, leaving every other section intact. Cut off ends of cucumber and slice into 1-inch rounds. Using a melon baller, scoop out the seeds and inner flesh from the top 2/3's of each cucumber slice. Do not scoop all of the way through. Set aside. In a bowl, combine equal parts cream cheese and sour cream. Mix in salmon, shallots, lemon juice, salt and pepper, combining thoroughly. Transfer the mixture to a pastry bag with a star 8 tip. Pipe the filling generously into each cucumber section. Garnish with sprig of dill. As an alternative, use red pepper cream cheese.