SAN FRANCISCO/NEW YORK (Reuters) - Facebook Inc is set to raise up to $18.4 billion in its IPO and become the first U.S. company to be worth more than $100 billion at its debut, as investors bet on a big pop in the stock when it begins trading on the Nasdaq on Friday. Frenzied demand, especially from individual investors hoping to buy into an Internet juggernaut that touches hundreds of millions of people every day, is expected to drive Facebook well above its initial public offering price of $3