Sprinkle salt over tomatoes in colander and toss gently. Let drain 10 minutes. Combine bell pepper, jalapenos, onions, scallions, garlic, parsley, pepper & lime juice in a mixing bowl. Toss gently & stir in drained tomatoes. Let stand at room temperature 30-60 minutes.
Heat beer and crab boil seasoning to boiling in bottom of steamer. Place shrimp in steaming rack & steam, tightly covered for 2 minutes. Stir once, then continue to steam until shrimp turn pink, 1-2 minutes longer.
Transfer shrimp to serving platter. If salsa is too watery, pour off excess liquid. Add salsa to shrimp & toss to combine. Serve hot, at room temperature or chilled.