Wash the potatoes, but don't peel them. Boil in water until tender, then drain and set aside to cool.
While the potatoes are boiling, fry the bacon until crispy, then crumble it up into pieces. Leave the frying pan on, and add the bread crumbs and toss them around in the fat until they become golden and crisp.
In a large bowl, mix the sour cream with the bacon, and some salt and pepper to taste. Hold back some of the bread crumbs, but mix the rest into the sour cream.
If you are using salad or new potatoes, cut them in half; if you are using whole large potatoes, cut them into chunks.
Toss the potatoes in the sour cream, and garnish with the remaining breadcrumbs. Sprinkle, if desired, with a fresh herb such as parsley or chives, or with chopped green onion.