When aircraft are assembled, the internal wing structure is attached to the skin of the wing using rivets. Traditionally a technique called backdrilling is used where holes are drilled from the inside of the wing out, and these holes then act as a targeting point to drill back inside. Not surprisingly, this is tricky to do and costly if you get it wrong. It also reduces the lifespan of the wings.
AB Electronics created the Halosensor, a handheld unit that uses a sensor array, drill block, targeting computer, and vacuum attachment system. The operator uses the display on the targeting computer to steer the unit to the desired position, after which the unit is locked to the surface with the vacuum system and the surface is either marked for drilling or the holes are drilled. The technology has also been adapted for robotic drilling. Because the system positions the hole from the outside in, resulting in greater accuracy and tighter tolerances, the manufacturers can remove material from the feet of the ribs (because they know exactly where on the foot the hole will be drilled). This in turn leads to an overall decrease in the weight of the plane and improved fuel consumption. Just from drilling holes accurately!