1. Combine tomatoes, jalapeno, lime juice, onion, and oil in a large bowl. Sprinkle with 1 1/2 teaspoons salt. Let stand at room temperature until tomatoes release their juices, about 1 hour. Toss with half the cilantro.

2. Bring a large pot of salted water to a boil. Add pasta, and cook until al dente, about 8 minutes. Drain, and rinse with cold water.

3. Toss pasta with tomato mixture. Stir in remaining cilantro, and adjust seasoning with salt, pepper, and lime juice. Serve immediately.