In a small bowl, combine tomatoes with 1 cup boiling water; let stand until soft and pliable, about 15 minutes. Drain tomatoes.
Meanwhile, cut baguette diagonally into 24 slices. Arrange on a 12- by 15-inch baking sheet. Broil 4 to 6 inches from heat until toasted on each side, about 2 minutes total.
In a food processor, finely mince tomatoes, onion, garlic, capers, and oregano with lemon juice and balsamic vinegar. (Or with a knife, mince tomatoes, onion, garlic, capers, and oregano, then add lemon juice and vinegar.) Add salt to taste.
Spoon tomato mixture into a small bowl and accompany with toast. Spread tomato mixture onto toast to eat.
Nutritional analysis per piece.