Using a vegetable peeler, shave the zucchini into thin ribbons until you reach the seedy core. Spread the ribbons out on a cutting board and sprinkle liberally with salt. Let sit for 20 minutes. Rinse the zucchini well, then gently pat dry and transfer to a small bowl. Toss ribbons with lemon juice, olive oil and chopped parsley.
As soon as the bread comes out of the oven (or toaster), rub one side of each slice evenly with a garlic clove. You won't use the entire clove.
Top each slice of toast with half of the marinated zucchini. Finish with a sprinkling of crumbled feta and freshly ground black pepper. Enjoy immediately.