As part of a shift to ultra-thin notebooks, HP tonight launched two crossover 13.3-inch notebooks that it hopes are both fast and portable. The ProBook 5310m is unofficially the most portable full-performance notebook ever with an 0.93-inch thick body (versus Apple's 0.94 inches) and a 3.8-pound weight; it accomplishes the feat through an aluminum shell without an optical drive and, unusually, by giving the option of a full-speed 2.26GHz Core 2 Duo as well as a CULV-based 1.2GHz Celeron dual-core. Using the Celeron gives the system as much as 7 hours of battery lif
