Peel the shrimp (saving the shells to use in a soup!). Devein them and pat them dry.

Cook garlic, red pepper flakes, and sea salt in oil in a 12-inch heavy skillet over moderately low heat, stirring occasionally, until garlic is pale golden, four to five minutes. Increase heat to moderately high, add shrimp, and cook, turning occasionally, until just cooked through, three to four minutes. Remove from heat and stir in lemon juice.

Transfer to a serving bowl and serve warm or at room temperature, with lemon wedges.