After September 11, it's no surprise that American businesses are beefing up the number of security guards manning lobbies, parking lots and office towers. The nation's two largest security firms expect to hire a combined minimum of 10,000 to 15,000 new guards, according to the Los Angeles Times. U.S. businesses currently employ about 745,000 private security guards.

Plus, U.S. officials estimate that federalizing airport security, under consideration in Washington, could require as many as 28,000 new hires. Air marshals for domestic flights could necessitate thousands more.

But the effectiveness of these measures is questionable. Most guards receive little training, are paid less than $10 an hour and typically do not carry weapons. Turnover is also a problem. In 1999, more than one-third of guards were in their jobs less than 11 months, according to the Labor Department.