Preheat oven to 350°F. Cut pita breads into wedges and place on a baking sheet. Toast until lightly browned and crisp, 10 to 15 minutes, turning once halfway through. Transfer to a plate to cool.
In a food processor, combine beans, oil, and lemon juice; season with salt and pepper. Purée until smooth.
Place purée in a serving bowl, and lightly sprinkle with chili powder. Serve dip with toasted pita triangles or plain pita wedges.