Combine 8 oz. softened cream cheese, 1 cup sour cream, 1/4 cup mayonnaise, 3 Tbsp. lemon juice, 6 finely chopped scallions (white and pale green parts only), 2 chopped garlic cloves and 3/4 tsp. cayenne in a large bowl; whisk until well blended. Gently stir in 2 (6 oz.) cans crabmeat (drained); season with salt and pepper. Chill for at least 1 hour before serving. (Dip can be made a day in advance; cover and refrigerate.) Serve with crudité or toasted pita.