Neff is U.S. chairman of Spencer Stuart, the firm that dominates the market for U.S. board searches. Spencer Stuart has recruited directors for giants like Wal-Mart , IBM , AIG , and General Motors . In his spare time, Neff has conducted CEO searches at Merrill Lynch , Sprint Nextel , and Boeing .

“More and more board candidates are saying that it’s just not worth it,” Neff says about the challenge of recruiting star executives for corporate boards. Since Sarbanes-Oxley became law in 2002, a typical corporate director’s time commitment has risen sharply. “I’d say by 50%,” he estimates, to about 200 hours a year. And for a troubled company (that’s most companies these days!), reputation can be a major turnoff. “Who wants to have their picture, along with a dozen other directors, in a New York Times story about a company in trouble?” Neff asks.

Moreover, compensation often doesn’t make up for the hassle. After Sarbanes-Oxley was enacted, director pay increased some 15% annually, Neff says. It’s still rising, but at a much lower rate. Today a directors at the top tier of Fortune 500 companies typically pocket about $200,000 a year.

So companies are forced to be flexible. Some are moving board meetings to easy-to-access locations — say, from a small town where a company is headquartered to a major metropolitan city. The biggest companies provide air transport for directors. “Retired CEOs who had their own plane typically won’t join a board if the company doesn’t provide a private plane to the meeting,” Neff explains.

Indeed, retired CEOs and big swinging shareholder activists. Remember when Carl Icahn forced his way onto the board of Blockbuster ? Icahn, who doesn’t like to leave New York City, got Dallas-based Blockbuster to move its board meetings to his hometown. That’s power.

P.S. For more on Neff and his longtime headhunting rival, Gerry Roche of Heidrick & Struggles , see my 2005 Fortune story, Clash of the CEO Kingmakers.