Bring water to a boil, stir & cook until al dente (about 9 minutes). Rinse, drain & cool. Drain artichokes, reserving liquid in a small bowl and coarsely chop. Add oil & vinegar to reserved liquid. Whisk together and set aside. In a large bowl combine orzo, artichokes, onion, feta, olives and tomatoes. Pour dressing over pasta and stir gently. Add salt & pepper to taste.
Serve at room temperature. Makes 8-10 one cup servings.