1. Preheat oven to 350°.
2. Arrange pitas on a baking sheet. Bake at 350° for 12 minutes or until toasted; cool 1 minute. Tear into bite-sized pieces. Combine pita pieces, fennel, and next 4 ingredients (through cucumber). Sprinkle with 1/4 teaspoon salt and 1/8 teaspoon pepper.
3. Combine juice, vinegar, oregano, remaining 1/4 teaspoon salt, and remaining 1/8 teaspoon pepper. Gradually add oil, stirring with a whisk. Drizzle dressing over pita mixture; toss to coat. Serve immediately.