Scrub potatoes with vegetable brush under cold running water. Prick potatoes with fork in several places. Place on baking sheet and bake until tender, about 1 hour. Cool 5 minutes.
Cut potatoes in half lengthwise. Scoop out potato, leaving a 1/4 –inch thick shell. Arrange shells on baking sheet.
In large bowl, combine potato centers, milk and sour cream and mash. Fold in the avocado, cheese, jalapeño and salt. Divide mixture evenly among potato shells. Bake until the cheese has melted and the potatoes are starting to brown, about 18 to 20 minutes.
Nutritional Analysis per serving: 168 calories, 7 g protein, 24 g carbohydrates, 5 g fat, 3 g saturated fat (29% of calories from fat), 12 mg cholesterol, 2 g fiber, 212 mg sodium.