1. Bring rice, water, and 1 t salt to a boil in a 1 1/2-2 quart heavy saucepan, then reduce heat to low and cover pan with a tight, fitting lid. Cook 20 minutes.
2. Remove from heat and let stand, covered, 5 minutes. Remove lid and fluff rice with a fork.
3. While rice is cooking, puree cilantro, onion, scallion, jalapeno, lime juice, olive oil and remaining 1/2 t salt in blender( if necessary add 1 to 2 T water to facilitate blending).
4. Add mixture to rice and stir with a fork until combined well.