1. Heat large, covered saucepot of salted water to boiling over high heat. Add pasta and cook as label directs.
2. Meanwhile, in large serving bowl, whisk peanut butter, soy sauce, vinegar, oil, lime juice, and crushed red pepper until smooth. Cut red pepper and unpeeled cucumber into matchstick-thin strips. Chop cilantro.
3. Drain pasta. Rinse with cold water; drain. Add pasta, cucumber, red pepper, and carrots to sauce in bowl; toss to coat. Sprinkle with cilantro. Makes 6 main-dish servings.
Note: If you have extra time, add one or more of the following: 1 cup fresh bean sprouts, 1 cup sliced radishes, or 2 green onions, chopped.