In A Small Bowl, Beat Cream Cheese And Butter Until Smooth. Stir In The Blue Cheese And Walnuts. Spread Evenly Over Toasted Bread. Place On A Baking Sheet. Broil 3-4 In. From The Heat For 3-4 Minutes Or Until Cheese Is Bubbly. Core Pear And Cut Into 30 Thin Slices. Place Two Pear Slices On Each Crostini. Serve Warm.