Brush baguette slices with olive oil; place on a baking sheet. Broil until toasted and crisp. Cool completely.
Toss peaches gently with vinegar. Top crostini with peaches and blue cheese. Sprinkle with pepper, if desired. Broil until cheese is hot, soft, and very lightly browned.
From Good Day for a Picnic by Jeremy Jackson (William Morrow, an imprint of HarperCollins, 2005)