Place tofu on several layers of paper towels; cover with additional paper towels. Let stand 1 hour, pressing down occasionally. Sprinkle slices with salt.
Lightly spoon flour into a dry measuring cup; level with a knife. Place flour in a shallow dish; dredge tofu slices in flour. Heat oil in a large nonstick skillet over medium-high heat. Add tofu; brush half of barbecue sauce over tofu, and cook 2 minutes. Turn slices over; brush with remaining barbecue sauce, and cook 3 minutes or until tofu is glazed. Place 2 tofu slices on bottom halves of buns; cover with tops of buns.