HP formally launched itself into the ultrabook space early Wednesday with the Folio 13. The 13.3-inch system is "less than" 0.7 inches thick and, while heavier than the MacBook Air at 3.3 pounds, also has what HP claims is the longest-lasting battery in the class. At nine hours, it can last for up to two hours longer than the Air, although Apple's tests are usually real-world where HP's are theoretical.
