Preheat oven to 325 degrees F.
Place sun-dried tomatoes in a small bowl and cover with warm water. Let stand until tender. Drain.
Meanwhile, cut pita into triangles, place on a baking sheet and toast for 10 minutes.
In medium bowl, combine mayonnaise, sour cream, bacon bits, and sun-dried tomatoes. Add a pinch of salt and pepper. Use a spoon to mix together; set aside.
Cut out the core of the lettuce head to form a bowl for the dip.
To serve, spoon BLT dip into hallowed out lettuce head and set in the center of a serving plate. Place toasted pita triangles around edge of plate.
Recipe courtesy of Sandra Lee, 2007