Dell updated its lineup of business notebooks today with a 2.5-pound laptop designed for executives who want to make last-minute changes to presentations while airborne. The Latitude X1 was designed with business travelers in mind, from its reinforced casing (which wards off shifting airline baggage in the overhead compartment) to a sealed keyboard that limits the damage caused by coffee spills. Dell reduced the size of this model"s power adapter and battery to reduce the system weight to 2.5 pounds, making this system the lightest laptop in the company"s arsenal.