Step 1 Bring a large pot of water to a boil. Add the corn and cook 3 minutes. Remove the corn from the pot and plunge into cold water to cover.
Step 2 Drain the corn, then slice the kernels from the cobs: Place each cob, stem end down, on the counter and, with a sharp knife, cut down on the cob. You'll have about 4 cups of corn.
Step 3Combine the corn, tomatoes, green onions, celery and basil in a large bowl. Add the vinegar and salt. Stir to evenly mix the ingredients.
Step 4Spoon into a lettuce-lined bowl and serve.