Fill a 4 qt pot three-fourths full with salted water and bring to boil for orzo.
In a small heavy skillet, heat 1/2 TBS olive oil over moderate heat until hot but not smoking and saute pine nuts, stirring frequently until golden, about 2 minutes; transfer nuts to paper towel to drain and cool.
In a large bowl, whisk together garlic, parsley, vinegar, salt and pepper; drizzle in remaining TBS olive oil, whisking all the while.
Add tomatoes and feta to the dressing, tossing to combine.
Cook orzo in boiling water until al dente; drain and rinse until just warm, then drain completely.
Toss orzo and pine nuts with dressing, coating thoroughly, then serve.