have to love the Onion:   WASHINGTON—Fax machines, despite using 40-year-old technology and having come into prominence in the 1980s, are actually still pretty impressive if you think about it, a new Brookings Institute report confirmed Tuesday. "Yes, the words 'fax machine' evoke this arcane image of a bulky telephone apparatus that makes a dial-up modem sound, but come on, if you take a step ba…