These are awesome. I tried these one night at dinner with 6 people, and all agreed that they could eat these beans as the whole meal and forget everything else. I used pepper bacon which added a little more pizzazz.
Cook beans in large pot of boiling salted water until crisp-tender, about 4 minutes. Drain. Rinse under cold water. Drain well. Pat dry with paper towels. (Can be prepared 6 hours ahead. Wrap in paper towels; enclose in resealable plastic bag and refrigerate.)
Cook bacon in heavy large skillet over medium heat until crisp. Transfer to paper towels and drain. Discard all but 3 tablespoons bacon fat in skillet. Add butter to skillet and melt over medium heat. Add shallots and sauté until tender and golden, about 4 minutes. Add beans and sauté until heated through, about 6 minutes. Add bacon to skillet and toss to blend. Season to taste with salt and pepper. Transfer to bowl and serve.