The Cash Heads Home (BusinessWeek Online) BusinessWeek Online - It's a cash bundle that would have made Howard Hughes blush: As U.S. multinationals such as IBM  and Pfizer Inc. (PFZ) have extended their reach across the globe, they've built up a mountain of profits earned abroad -- as much as  #36;750 billion, by some estimates. That's more than the annual economic output of Hong Kong, Ireland, and Switzerland -- combined. And up till now, they've kept all that moolah overseas, much of it in tax havens such as the Bahamas, Ireland, and Singapore to avoid the stiff 35 levy they'd face if they repatriated the funds back into the U.S.